Sorry, but that makes absolutely no logical and/or commercial sense. The market doesn't want or need an art piece for a Mac Pro. The market has been demanding a Mac OS driven powerhouse to do heavy computational lifting.
Design a "nice" case with modular capabilities for users to be able to replace/upgrade off-the-shelf RAM, SSDs, GPUs (Nvidia AND AMD!), generous standard I/O options to include a headphone jack. Use this as an opportunity for the rebirth of the Mac Pro line and recapture the goodwill of creatives and computing scientists/researchers. Then, make nice design tweaks while NOT taking away from functionality with each annual iteration.
This isn't rocket science! All the parts, chipsets, motherboards, RAM, SSDs, GPUs, etc. are readily available from 3rd-Party manufacturers. This is what Apple has done for decades and it's resulted in stellar profits.
They can also provide a scaled down version as the *new* Mac Mini for those that want Mac OS at a more approachable price point. Think of schools, uni students, etc that might want to create but can't afford a $3000 rig. This is where you can get people building great AR, VR, AI, ML systems and other "things" yet to be imagined. Remember Steve talking about "The intersection of technology and liberal arts."?
Building overheated trashcans for the sake of design kudos and personal hubris leads to dead ends and lost profit. Of which they've already admitted to as a major technological and commercial mistake. “I think we designed ourselves into a bit of a thermal corner, if you will,” attributed to an Apple Executive back in 2017.
Apple has lost its way!