I think they'll keep some form of iMac going.
It's perfect as a "lifestyle" computer.
I routinely see them in medical offices (often dentist or orthodontist).
iMacs are extremely popular in the backgrounds for YouTube content creators.

Seriously though, I have repeatedly seen them in school computer labs, row after row of iMacs, both in universities and high schools. A lot of those labs still have Intel iMacs, but I've already seen them with Apple Silicon iMacs.
Yeah, they could go with Mac minis and external monitors, but I just never see that. You generally lose Retina support unless you go with Apple monitors or top of the line third party monitors. However, Apple monitors are too expensive for this purpose, at least for publicly funded schools. And if you go with third party monitors, whether they be cheap ones or expensive ones, colour management becomes more complicated, and you start running into other issues such as wake-from-sleep problems, etc. with macOS updates. In fact, I've run into this problem myself. My third party monitors worked perfectly with Sequoia and Sonoma, but now on Tahoe I have sleep issues, so now I've set my M4 Mac mini up to never sleep.
with the redesigned m4 mac mini coming out end of 2024, i would be shocked if these numbers would still be the same in 2025.
Prepare to be shocked. Although the data currently remains scarce, initial 2025 estimates by some pundits still have the iMac easily outselling the Mac mini. 2025 Q1 estimates have the best selling laptop Macs being the MacBook Pro overall and the MacBook Air in the education sector, and the best selling desktop Macs being the iMac.
I do think the M4 Mac mini may outsell the M2 Mac mini, but remember, the unit sales of the M2 Mac mini were so low to begin with that even if Mac mini sales increased by 50%, they still wouldn't outsell the iMac.
BTW, I'd say I'm not biased toward the iMac, as I own an M4 Mac mini as my main computer, and before that owned an M1 Mac mini as my main computer. I haven't bought an iMac since 2017, and don't buy MacBooks for myself anymore either (although I did buy an M4 MacBook Air for my wife this year). And as you know, I just ordered a 6K 31.5" LG monitor to pair with my M4 Mac mini. Fingers crossed that I don't run into sleep problems or other compatibility problems with the LG 6K.