Ah, ok, that I really don't see the point.
PCs aren't vertically integrated from a single vendor, and thus it isn't as if Microsoft alone can drag a whole ecosystem into ARM, even if the emulation would work out great.
Windows NT was also multi-architecture, and eventually all variants died, because x86 was good enough, and when Itanium came to be, AMD got a workaround to keep x86 going forward.
Even gaming doesn't work that great on Windows ARM.
