That's assuming that they completely abandon Intel, which would mean that the Mac Pro would not be offered with a 28-core Intel Xeon W, but rather with an ARM p

That's assuming that they completely abandon Intel, which would mean that the Mac Pro would not be offered with a 28-core Intel Xeon W, but rather with an ARM processor that has comparable performance (or not offered at all). But even if Apple shifts to 100% ARM, Hackintosh community still has whatever number of years that Apple still has to support the computers that they are selling now / selling until ARM takes completely over.