I would be very surprised if they put out a M2 Pro mini. It would cut into the M1 Max Studio sales. It isn't Apples goal to maximize desktop volume by adding more incremental price points. Their goal is to maximize profits, and the entry level Mac Studio will sell well at $2000. If they wanted a Mx Pro Mini they would have already introduced an M1 Pro Mini last October when they introduced the M1 Pro MacBooks. I think they have created 3 tiers of desktops and the Mini will be the low-end only tier once again. The Mac Studio will be their broad mid-tier desktops at 2 basic price points, and the Mac Pro their elite upper-end desktop. My guess, of course.
Going from 16Gb RAM to 32Gb RAM on an Intel i5 Mini costs $400 so we have a known update pricing from Apple. Apply this to an M1 Mac mini with the same 512Gb SSD as the base M1 Max Studio CPU and you have the following:
$1099 - M1 16Gb RAM, 512Gb SSD
$1199 - M1 16Gb RAM, 512Gb SSD, 10Gig Ethernet (to match the Studio)
$1599 - M1 32Gb RAM, 512Gb SSD, 10Gig Ethernet - this spec doesn't exist obviously
Now, we add a mythical CPU upgrade for M1 Pro, there's no known Apple jump from M1 to M1 Pro so I will assign a not unreasonable $200 to it (difference between i5 and i7 Mini).
Your vastly upgraded M1 Mini now costs $1799 which is only $200 short of buying an M1 Max Studio. You can argue that you have no use for the 10Gig ethernet but the fact is you also get the high impedance headphone jack, 2 more Thunderbolt 4 ports, 2 more USB-C ports, and a superior cooling system. Plus, for people in the know, I assume Apple will have sorted the wifi/bluetooth issues from the classic Mini form factor.
Just like moderately upgrading the Mac Studio M1 Max, at some point you may as well spend the extra few $$$ and get the Ultra.
The argument should really be for Apple to upsell people who want 32Gb of RAM to the M1 Max Studio which has lots of extra bells and whistles - the pricing has to tempt people into calculating at some point that a Mac Studio is the better purchase.
The M2 will have a couple more graphics cores and probably slightly higher CPU benchmarks from being a generation newer but won't threaten the M1 Max at all. If Apple wanted to fill the $1099 price point they could achieve that by selling a 16Gb RAM/512Gb SSD M2 SKU as the 'upper' Mini.
They may be letting the Intel mini linger on for unspecified reasons. For example the co-location guys may want the Intel/M1 form factor to carry on not only because their data centres are configured for those form factors but I realised that Apple would have to continue making spare parts for the units if they carried over the existing mini with an M2 in October.
If Apple don't deem it a priority to 'fix' the Mac mini form factor could they actually be persuaded to carry over the Mini form factor because they want to be able to offer spare parts for repairing units in data centres? Only they will have the data on this.
And it just occurred to me latterly that Apple could even let the M1 continue for a generation in the MacBook Air and base mini (as base models in Apple's range) and offer the M2 in the MacBook Pro 13" and the upper SKU mini as a reason to upsell people. [I'll also be cheeky and suggest it would also up
set people here too

]
Future upgrades could then see the M2 drop to become the base model when the M3 comes out as upper SKU.
It would be equally Apple to go with the smaller form factor Mini that we've seen sketched if they wish to miniaturise and refresh the range too but such a miniaturisation would almost certainly rule out an M1 Pro.