Across Apple, to continue making x86 machines alongside ARM, is going to need a lot more than just the Rosetta software layer.
Rosetta doesn't help hardware design, R&D expenditures for this tiny handful of x86 machines OP is proposing Apple keep in the lineup. Those R&D expenses for just x86 development work are much harder to justify when its just the Mac Pro that benefits, not the entire computer line, too.
Across Apple, to continue making x86 machines alongside ARM, is going to need a lot more than just the Rosetta software layer.
Rosetta doesn't help hardware design, R&D expenditures for this tiny handful of x86 machines OP is proposing Apple keep in the lineup. Those R&D expenses for just x86 development work are much harder to justify when its just the Mac Pro that benefits, not the entire computer line, too.