Interesting point. This would suggest pretty sizable synergies from the oft-rumored Microsoft acquisition of Intel.
Microsoft proved with the XBOX and Surface series they can make good hardware if they want, now they need to move to chip design.
Microsoft has at least one homegrown processor that it has ported Windows and Linux to with the confusingly named 'Edge'.
https://www.theregister.com/2018/06/18/microsoft_e2_edge_win...
Microsoft doesn't even _need_ to target Arm, they could easily team up with AMD or go the whole thing solo and target anything from RISC-V, Arm to an in-house ISA.
What was the last version of Windows to support either of these platforms?
Could that possibly be approved by governments?