They could do what Apple did when they replaced the old MacOS with UNIX, which is they shipped an emulator for a while that was integrated really well. They also had a sort of backwards compatible API that made porting apps a bit easier (now removed, it died with 32 bit support).
But in the Windows world, third party drivers are much more important. So in that regard it would be more difficult. Especially if they’re not fully behind it. As soon as they waver and there is some way to keep using traditional Windows, the result will be the same as when they tried to slim down the Windows API on ARM, and then nobody moved away from the APIs that were removed because they still worked on x86, which significantly slowed adoption for Windows on ARM.
They could do what Apple did when they replaced the old MacOS with UNIX, which is they shipped an emulator for a while that was integrated really well. They also had a sort of backwards compatible API that made porting apps a bit easier (now removed, it died with 32 bit support).
But in the Windows world, third party drivers are much more important. So in that regard it would be more difficult. Especially if they’re not fully behind it. As soon as they waver and there is some way to keep using traditional Windows, the result will be the same as when they tried to slim down the Windows API on ARM, and then nobody moved away from the APIs that were removed because they still worked on x86, which significantly slowed adoption for Windows on ARM.