I like the direction that Apple's going in right now, and as other users have stated I think there's a clearer difference between their consumer vs pro lines. However, that being said, it seems like the Pro line is getting more of a focus now while the consumer segment still needs a bit more attention?
Here's what I'm hoping for in the future Mac line-up as Apple starts to address all market sectors.
Consumer:
MacBook Air: 13", 16"
iMac: 24", 27"
Mac Mini
Pro-Sumer (mid-tier somewhere between a consumer and a pro):
Studio Display: 27" with Camera & Speakers, 27" without Camera & Speakers
Mac Studio
Pro:
MacBook Pro: 14", 16"
Cinema Display: 27", 32"
Mac Pro
I think there's a use-case for a consumer level 27" iMac, but I'm not sure how large of a market they have to justify building them. Judging from the posts here, it seems like there's a large enough market. It makes more sense to push anyone who requires pro-specs to a separated Mac mini, Mac Studio, or Mac Pro with a paired display. It reduces e-waste and you're able to upgrade the computing without tossing out a perfectly usable display.
The world of e-waste is a real thing, and the industry is rife with issues. Also, gold is a limited resource which is also needed in electronics:
[Edit: There's a much better way to address e-waste in the consumer level market, since this might be their largest selling market. Pro being more niche. If they sold the iMacs screens at 24" and 27", but turned the stand/base into a computer, customers could update their iMacs stands (the computer) without tossing the display. There's plenty of creative solutions that won't sacrifice aesthetics when addressing e-waste and the iMacs. Why Apple doesn't? Who knows? An interchangeable iMac stand that has the guts of the computer, would be a much better way to reduce consumer level e-waste.]
With the suggested lineup above, I think Apple could cover almost all of the markets. I read a post mentioning a plethora of designers and creatives who were using the 27" iMacs in-studio. I use to work in-house, contracted, at a studio from 2017-2018 filled with 27" iMacs (not an iMac Pro, or Mac Pros). I had an iMac 27" from 2016-2017. The main reason that particular studio was using the 27" iMac was for the 27" screen. Since it was built right into the unit, it was less of a headache for the studios to deal with than trying to setup the LG screens since Apple had discontinued their Displays starting 2016. Other in-house studios prior to 2016, in my experience, had both PC and Macs. I was set up with a Mac Pro and Third Party color accurate monitor.
Mac Pro segments are tiny within the entire creative field: 8k videographers, special effects houses, animation, 3D heavy industries, maybe even real time simulations that need procedural calculations (though this segment isn't creative, more scientific). There are other segments like typography, print, graphic design, illustration, photography (wedding, corporate/commercial, personal or professional), product design, and drafting types that don't require Mac Pro level of computes. I feel like, the Mac Studio is targeted towards this market, and I think it addresses those industry quite well.
I don't really understand who the iMac Pro is for? If I remember correctly, it was MKBHD who begged Apple for an iMac Pro. Once the M1 series of MBP were released, he mentioned not needing lug around his iMac Pro to edit on the go and was all in on the MBP.
The Mac Studio addresses the iMac Pro segment quite well. Yes you won't get the compact all in one, but at a mid-tier level this segment is covered. The rest is merely about aesthetic and convenience. The Mac Studio isn't some beefy tower and it's footprint is relatively small. The aesthetics are maintained and your desk won't suffer from too much clutter - with front facing ports for functionality to* boot.
If there's going to be a 27" iMac offering, I would be content keeping it at the consumer level with the 24" iMac. I think letting the Pro-Sumer + markets move towards the separate Display + Computer setup is ideal. Apple Displays last a long time and aren't updated often, better for the environment overall to keep them in a separate housing. I like the direction. I also feel like Apple is really starting to focus on and address the Pro market again, which I'm happy to see.