I'd speculate that the higher-end 24" iMac was supposed to be M1X - which would explain the otherwise bizarre decision to have two slightly different models, one with better cooling and more ports. Just a guess, though. Even without that, though, launching the 24" iMac before the flagship 16" MacBook Pro, which you'd expect to be #2 priority after the Air, was a bit of a surprise.
The 24" iMac chassis redesign points against the "M1X'. It is relatively clear Apple was out to gut as much thermal cooling capacity as possible with the new case design. ( Ethernet chucked to the power adatper. Can't even get audio jack on the back because it is so thin. ). It is down to about the thickness of the LCD screen panel and see if there is some left over space for the computer part. It is a 24" ipad in terms of primary chassis design.
The other problem for the 24" is price.
i. the bigger die 'M1X' will cost more than the smaller M1 die. The SoC will cost different.
ii. What Apple hasn't replaced from the old 21.5" Mac line up yet is the "edu" , non-Retina iMac with the ancient MBA processor.
When the M2 comes out the "full port" iMac 24" could be moved to the new chip. When "higher end" boils down to a couple more ports there isn't much of a differentiation happening. The more cripple port model could just keep the M1 chip. Wouldn't be surprising if Apple gutted the motherboard of Ethernet support and maybe crank down the screen to pay for a price cut back to "edu" iMac prices. Once Apple has a M(n-1) or M(n-2) part to use they can use that trailing end part to sell a cheaper iMac. To jumpstart the path they are just using the only single one they have now ( and keeping the Intel alterantive around. It is over on the 27" iMac "buy" page, but it is still around. )
This would be very similar to what Apple has down with the iPad. "regular" iPad versus iPad Air. the former is often used as tool to sell to the "edu" market.
In short, gimping the ports gives Apple a path to cut costs later.
As far as "high priority"... 16" before iMac was extremely likley lower priority to growing the M-series powered systems ecosystem as fast as possible. That is way Apple lead with the lower cost M1 systems. The objective was probably to stop buying as many Intel CPUs as fast as possible. That meant taking everything that were the highest volume sellers in the lower "30%" of the line up that could be powered by an M1 and flipping them over almost all at once. MBA and MBP 13' two port were probably highest volume. The Mini was just "too easy" since the DTK had also just used it win an Apple chip also. It probably wasn't doing the volume that the MBA and MBP 13" were doing but it was just move volume to throw onto the pile. ( Plus they could push discounts at the lower end through Amazon, BH , etc. to soak up any production volume estimation adjustments they needed to do. Push a decent discount on the lowest end configuration and drawn in those looking in from the outside the lowest entry price. ) . Between the 21.5" and 27" the smaller one was very likely the highest volume seller. Putting all the volume sellers onto one chip makes it cheaper for Apple. Much cheaper.
Putting a variant of the "M1X" into the "larger screen" ( 27" - 32" whatever Apple picks) will help differentiate the two iMacs ( just like before when separated by CPU+GPU combos. ) That 27' model can better soak up the higher price of the "M1X". And if Apple doesn't go crazy thin on the 27" it would have better thermals too. [ go back more to the box with thickness shape of the XDR and pre "thinnest edge" iMac design shift. so not constrained to stuff the electronics in the chin because there is no room behind the screen for anything substantive. ]
The M2 will be more "powerful" than the M1. The M3 will likely supercede the M2. The iMac 24" can get to "more powerful" models by just following that update track. It really doesn't need the 'M_X' to do that. Apple has been doing lots of spinning over last several years about how the iPad Pro chip ( 12Z , 12X ) were 'desktop' like .
The system that is far more likely to be split M1 and "M1X" is the Mini. There is gobs more Thermal headroom in the current Mini chassis. There is also gobs of money already invested in lots of data centers and racks in custom holders to put lots of Minis into the rack , shelf, custom cabinet , etc. Selling something that just slots right into where it fits makes far more sense that Apple making those folks go back and spend another round of money for new holders and enclosures. Money spent on that is just less money that could be spent on a new Mini.
The more common low end use desktop customers could get a new "thinner" enclosure with better Wi-Fi ( which is next to useless in a rack/enclosure deployment in vast majority of cases ) and perhaps an incrementally smaller desktop footprint. That thinner Mini case goes on the M1 , M2 , M3 track and the classic Mini base chassis goes on the M1X , M2X , M3X track.
From what I've seen, all we know is that it has three USB type C sockets (of unknown capability) and a HDMI socket (of unknown version) and some sort of Magsafe connector.
Best case:
3 x independent TB4 ports (supporting 2 displays) + 1 x Ethernet-over MagSafe + independent HDMI 2.1
That would fail TBv4 certification. A host system has to be able to do video out concurrently on all of the TBv4 ports to certify for TBv4. ( Most of TBv4 is about dropping optional features. One of TBv3 options feature is shorting on provisioning the TB controller on PCI-e and DisplayPort (DP) inputs . TBv4 removes that. )
The TB and HDMI 2.1 ports could share a DP stream and probably still pass. But if the "independance" of the HDMI port was having its own private stream then would need a four stream SoC. Apple probably isn't going to provision HDMI 2.1 either because it is going to be a conversion of a DisplayPort 1.4 streams coming of the TB controller.
The Apple SoC doesn't provide Ethernet. I'd be surprised if they were up for scaraficing larger logic board space and power to a discrete Ethernet controller. Yes, Apple probably got some space back by absorbing other stuff into the "M1X" SoC, but they are probably more interested on "spending" that on bigger battery than logic board space. The other thing is Apple is probably not looking to put a bigger MagSafe connector on the side.
MagSafe is likely going to do two things. First, charge the bigger battery faster ( which also might take up logic board space that a discrete Ethernet controller would occupy). Second, it gets around the fact that Apple gimped the number of TB ports. Dropping one of the TB ports on the right side for a HDMI port means down one TB port. That's the port that could have held the USB-C power supply cable. If also need to use a USB-C Power port now down to just two TB ports. Two ports is "low end" MBP 13 territory, not $2.5K laptop territory. MagSafe solves that problem that the HDMI port creates.
The large battery in the MBP expands out to the outer edges which is the primary driver of the highly limited edge space for ports. The Apple SoC probably reduces overall power consumption but super, ultra bring mode microLEDs are probably a net increase from that subsystem. The increased "bump" in battery life the M1 systems got is probably going to be lower than the bump the "M1X + microLED" systems get.
Worst case:
2 x TB3/USB4 + 1 x USB-C 3.1 + HDMI 1.4 or 2.0 (good enough for Keynote presentations)
Best case needs a substantially expanded M1X with more I/O and display support... the "worst case" scenario could probably be implemented with a warmed-over M1 by including an on-board TB hub to share the single external display output with the HDMI. That would suck and be a huge disappointment, but the leak doesn't rule it out.
Extremely unlikely. On Macs, Apple has consistently used the Type-C connector for Thunderbolt. Probably not going to change paths now. The four port MBP 13" and MBP 16" all have TB ports. Going to USB-C only for one of those ports is huge backslide fo very likely zero decrease in the overall system price. Enough folks have grumpbled about SD card and HDMI that dropping one TB ports and still charging the same price would work. Bringing back just regular MagSafe makes that even more likely. That is also a source of complaints and as outlined almost necessary since nuked a TB port.
There are tons of deployed high quality monitors out there with HDMI 2.0. The notion that all of those were just "bottom dwelling PowerPoint only worhty" monitors is goofy.
Apple has a "warmied over, incrementally bumped" M1 coming in the M2 (in 5-10 months. Get outside the initial demand bubble for the A15 and then shift some wafers over to making the M2. ). The "M1X" absolutely does not need to be the "early arrival of the M2" SoC. It is a bigger die that does more.
A TB or USB hub on the inside of the system would use more power than if the TB and/or USB was integrated on the SoC. Apple's SoC program is all about performance/power. There is little likelihood they would pass up a power saving solution that they already have a solution for in the SoC. All they need to do is use a bigger die to Thunderbolt and/or USB-C which they already have.
For the number of display they need some more display controllers and more bandwidth. The display controllers they already have with the limit of 2. Just need more. The bandwidth would come with using one or two more RAM stacks ( and associated memory controllers).
The worst case would be that Apple kneecaps the "M1X" with some artificially low die space increase. The A14 is about 85mm^2 and the M1 about 120mm^2 ( as were previous iPad Pro chips.) . Worse case would be some arbritrary rule that said "can only add 40mm^2 becuase that is gap between A-series and old A_X series. ( can only go to 160-180mm^2 because trying to save a couple bucks. )
That, of course, assumes that the leaked schematics were/are ever on course to become an actual shipping product.
Given that these were
stolen from the contractor means they are likely real. This wasn't a leaker out to get ad page views or reputation. It was a ransom threat. Can't ask for lots of money for "fake" stuff. Quanta and Apple knew the hackers were coming so set up a super elaborate , fake honeypot to draw them in...... probably not.