They could do it, but will they?
Both models would need to have the same type of hardware, except for GPU performance and storage space/speed. The GPU would need to be the same model, just less CU's in the base model and much more in the Pro model. The Pro model could also use some extra RAM.
This should make scaling games for devs quite easy, so both consoles should be well supported from the start.
The Pro version would probably end up XB1 size, and would require a 300w-400w PSU, which is a lot, but doable.
The base PS5 can be dynamic 4k/60, while the Pro model must be true 4k/60 at all times.
$399 & $599, or $349 and $499. Above $500 at launch could defeat the purpose of a Pro model that early and only lead to the same level of sales PS4 Pro is getting now.
All PS5 games must work on both systems without one or the other feeling broken.
The gen may have to be reduced to 5 or 6 years overall, or have a mid gen upgrade again anyway after both.
I won't be buying PS4 Pro because I can't be bothered now that my PS4 is good enough. Had the Pro been available since launch, I would have gotten it after a year or two instead, when the price came down, and so would most of my friends. We won't upgrade once we make a choice each gen though. Is it better to make the spec hungry gamers wait 3 or 4 years?
I think solving problems like having proper full support for both models from the start due to a more equal user base, would far outweigh a large power hungry console. It's not like they won't shrink it after 2 or 3 years if you require that and would wait that long for a mid gen refresh anyway.
