It's just increasingly silly in the Azure and server space to be running Windows--you lose all the benefits of the container ecosystem and have all the baggage of decades of windows cruft (yes I know windows containers exist--no one uses them). Desktop usage has been in decline forever and I have to imagine they could get the 90% of windows API apps left that matter to work great on wine. It would give Microsoft a huge boost to get back in ARM by building on the linux kernel and its great support vs. windows ARM very limited set of qualcomm and a handful of other chips.