Thicker? The iMac Pro is already "thick". All they have to do is not thin it out in the first place. If you don't paint yourself into a corner in the first place than don't need some "revolutionary" solution to get you out of that very same corner.
iMac Pro 2017
" ...
| Power Consumption (230V/50Hz) | Thermal Output | | |
| Idle | CPU Max | Idle | CPU Max |
| 64W | 370W | 218 BTU/h | 1,262 BTU/h |
..."
Learn about the power consumption and thermal output (BTU) of iMac Pro (2017).
support.apple.com
Mac Studio
"
- Maximum continuous power: 370W
"
https://www.apple.com/mac-studio/specs/
The iMac Pro has a bigger than 370W power supply that can deliver to the internal components 370W.
Apple is pushing this Studio as an old iMac Pro replacement. If Apple wanted to do a new iMac Pro that covered another space than the old one ( e.g. grow the screen size, square off the edges , add 'six speakers' , and even more comfortably provision a 400W allocation .. .they could. The biggest impediment is getting the design through the "ever thinner, no visible air inlets/outlets" design politburo than any technical thermal challenge.
If the Studio Display has some bleeding edge display panel I'd would somewhat agree. Instead what we have here is Apple selling mostly what would have been a $1799 iMac 27" gutted out wih a A13 inside for $200 less. It is repackaged tech probably could have rolled out two years ago. It isn't a leadge edge screen. It is a very affordable (high margins for Apple) and available screen.
That is substantively indicative that Apple can't get the screens they want at the volumes and prices they would like for a iMac Pro at the moment. A large chunk of that is due to issues out of ApplIf e's control. It is the wrong time for another large screen iMac.
If Apple offered a substantive bundle pricing discount for a Ultra+Screen discount there are a lots of folks who will take it. The folks who bought iMac Pro because there was no decent Mac Pro to upgrade to? No. But lots of folks buy iMacs and are not super agitated about the integrated screen.