Maybe I could see that for Windows server. As more of that market moves to azure, the os matters less.
I've heard rumors that the dom0 equivalent in their azure virtualization platform is now Linux based. They still use an in house hypervisor, but may have moved to Linux as the management stack.
It's a long shot, but if Microsoft were moving anything at all, it would be the server product given it actually struggles in market share.
On the desktop, they just don't have much reason. They barely evolve the NT kernel so it doesn't cost them a huge amount. The Linux approach to drivers would completely mess up their driver ecosystem. With the world of modern standby, windows pretty much gave up on long term suspend and instead hibernates, Linux refuses to even try to hibernate with secure boot. The features a Linux kernel brings to the table just do not matter to the windows desktop market. It would be a giant migration expense for no benefit compared to their current strategy of just hosting a Linux kernel as a virtualization guest.
I mean I would love to use a Linux oriented desktop management instead of Windows shell, but it's abundantly clear that would be non negotiable for Microsoft, so I'd end up still stuck with my least favorite part of the windows experience even if the kernel were Linux