Will Apple instead just drop both those lines completely?
Both? Extremely unlikely. The Studio is the replacement for the 'big iMac" segment in the price range. Apple highly likely isn't going to abandon that. The current "iPad on stick" and Mini put too many self imposed limitations on their desktop line up in terms of cooling and internal volume capacity. ( the iMac is largely restricted to the relatively narrow height/width 'chin' of the device for SoC placement. The Mini is a bit 'too big' for plain Mn but the Mn Pro is a tighter squeeze presuming want to stick with internal power supply). The studio avoids that but doesn't diveraege too far away from the constraints on the MBP 16" chassis restrictions.
The far over $10+ K workstation , maybe. But all they would have to do is decouple the Studio Ultra submodel from the Studio product. The Studio would still be around minimally with a "Max" option even ifthe "Ultra" SoC disappeared. (which it doesn't 'have to' . M1 Ultra did OK with no Mac Pro).
Or if Apple wanted to move the Studio at different speed : MP ( M4 gen -> M6 gen -> M8 gen ) and the Studio get M-odd Max stop gap fillers between 2 years gaps and no "Ultra". Presuming the laptops were on 12 month schedule.... which may not work out either. The long term slower the "Max' die size goes the slower the MP iterating more lines up. ).
Apple's deep refresh cycle on the Mac Pro has a been 4 years ( 2009-2013) , 6 years ( 20013-2019), 4 years ( 2019-2023 ). A highly regular, two year cycle would be way faster than their established average. Taking two years to do a 'refresh update' doesn't exactly scream 'abandonment by Apple'. It is just longer, but longer has been their modus operandi for over a decade. Why is that surprising?
That’s what I think will happen. The users (probably small compared to phones, tablets, laptops) could use PC workstations instead.
The hyper modular folks leave and the old iMac class collapses? The old iMac class were not highly composed of the hyper modular folks in the first place. Hyper modular folks leaving if a big 'huff' isn't going to substantively shrink the old iMac numbers.
For the Mac Pro .... sure that impact will be substantive , but Apple doing a longer refresh ( 2-3 years ) to a smaller crowd is an adjustment. Apple already shifted to an incrementally smaller crowd by increasing the entry price for Mac Pro 100% back in 2019. (and more than 100% if go back to the 2010 era $2,500 entry mark ) . The adjustment already has been established is to iterate slower.
A M4 Ultra with balanced two x16 PCI-e v4 backhaul feeds for the switch and M4 general uplift in CPU, GPU , and NPU would likely do Ok. It isn't going to be an general market workstation 'killer', but it doesn't have to be to pay for itself and keep the line up moving forward.
Going forward it is still going to be case that having more than one internal SSD drive is going to be useful for a subsantive number of folks that do not necessrily need a dGPU. I don't see the Mac Studio really fixing that role ( with 3rd parth xMac chassis to embedded the Studio into).
If Apple doesn't do an "Bigger than Ultra" SoC then there is a decent chance the Mac Pro will get inncrementally smaller ( loose the 1200W power support and a few slots while picking up something like TBv5 while keeping the small SATA options. ). Apple shifting to something that might be a better 2U-3U rack version would make more sense if they are going to 'dump' some major variant of the SoC into their datacenters in larger numbers. ( XCode cloud , AI cloud variants subsets to their datacenter deployments. )
Admittedly this is the same arguments used against the Intel Mac Pro.
The Intel Mac Pro still had the 'Boot Camp' option. Apple is probably going to need to work 'harder' when they don't have that. Either need a 'pass through' VM abilities or need to do some more deliberate work on broadening the PCI-e card market a bit more ( not necessarily opening the dGPU door , but lot less denial about 3rd party SSD market and other accelerator and i/O cards that add value. )
