Apple also helped by not copying the iOS Boot mechanism to macOS, which they could have. This entire "Permissive Security" mode allowing for installation without jailbreaking took extra work to make and was not necessary otherwise.

They probably want to entice arm windows and chromeos support longer term

Reading between the lines, Apple wanted Windows support at release, but Microsoft signed an exclusivity agreement with Qualcomm for windows on ARM so they weren't able to make that happen even if they wanted to.

It's fair to speculate that Microsoft likely has Windows already running on M1 machines somewhere deep within their labs. Even if it's just some engineers doing it "in their free time"

Wonder what Qualcomm had to do to get that agreement though. All signs seem to point to Qualcomm being absolutely poisonous to work with and their ARM offerings being uncompetitive with Apple's now

Is that ever set to expire?

Yes, quite soon (this year? next year?) IIRC