German has solid sources about development models Apple is working on so I believe Apple has a Mac mini with Pro class M family SoCs in the lab.
Whether or not they decide to ever release them out of the lab is the question.
Absolutely they will have tested M2/M1 Pro/M2 Pro in the existing chassis.
We are at the point, though, where US to Euro/£ exchange rates have changed to the point where price rises will have to occur for new product - see the M2 MacBook Pro for the example.
Marketing wise, if Apple replace the M1 Mini with M2 across the board then Europe and UK will probably see 50-100 Euro/£50-100 price uplift in the same chassis. Probably not a great look for the cheapest Mac in the lineup as we move into the possible recession although I think any new product is potentially liable to price increases in Europe/UK due to exchange rate.
For this reason I'm now leaning toward the M1 Mini staying in the lineup unchanged.
But the spec of the upper SKU Mini remains up in the air.
If Apple launch an M2 Pro Mini by October it'll be a great time to upgrade the 14" and 16" MacBook Pros (introduced in October 2021) but you'd then need to see M2 Max upgrade options - which looks bad next to the Mac Studio which was only launched in March. So adding the M2 Pro to the Mini might seriously cannibalise the Mac Studio which surely can't get a spec bump till March 2023 at the earliest.
Unless that's the plan and the upper SKU Mini isn't getting a release until 2023 to coincide with the next Mac Studio.
Apple's solution for the MacBook Air has been to keep the existing M1 model at the old price and introduce a (potentially redesigned chassis) SKU with M2 in or keep the same chassis and throw in higher power CPU.
At the moment, Apple have 2 good choices:
Keep M1 Mac (low SKU), introduce M2 Mac with price and spec increase (like MBA!)
Keep M1 Mac (low SKU), introduce M1 Pro based upper SKU (but no M1 Max BTO) - this would account for Eurasian database desktop model but remember that might be meaningless as it might have been referring to a redesigned Mac Pro.
And 2 other choices:
M2 update across the board (will lead to price increases in Europe and UK) replacing M1 in same chassis
M2 update plus M2 Pro upper SKU - is it really a great idea for the Mini to get the M2 Pro first ahead of the 14"/16" laptops? Sounds like this doesn't get a release till Spring 2023 in part to give plenty of time for other higher value Macs to get sold first.
M1 Pro Mini would offer distinct upgrades over the M1 including at least 3 Thunderbolt 4 ports, likely 10 Gig ethernet option and potential for SD slot alongside HDMI (looking at the MacBook Pro 14/16 as template). It would also bring plenty of horsepower - perhaps enough to steal sales away from the Mac Studio.
An M2 Mini alongside a base model M1 would only offer the same (significant) incremental in-chip speed upgrades that we are seeing in comparisons between M1 and M2 MacBook Pros. I would suggest that Apple could probably get away with it by pricing up with 512Gb base storage (for example) for the starting SKU.