I suggested on Mini-Microsoft about 10 years ago that Microsoft do an 'Apple'. Apple took a free OS from BSD and put their own GUI over the top of it. I suggested that MSFT do the same sort of thing, that being to put their Windows GUI on top of the Linux OS instead of using the Linux X11 GUIs. This had the advantage that the underlying OS base would no longer need maintaining by Microsoft, and all their coding effor…
Apple only needed to support their own hardware. Microsoft would need to make Linux work wherever NT works, and would need to figure out a solution for third-party closed-source NT drivers. Besides, in a sense, Microsoft did this when they moved the desktop product line to NT. It wsa a similar compatibility break and a similar improvement in stability and switch to a robust, multiuser, preemptively-multitasking kerne…
After a couple years, they could make Windows server run on a Linux core, and then another couple years have Windows run on Linux.
The whole progression could be pretty smooth, covering several years and taking a milestone-driven approach.
With the surface, im sure hey could use that to their advantage and have kore control over hardware.
Perhaps the best impetus to do this would be if they ever really wanted to migrate to ARM and reduce their reliance on the intel platform.
The hardware piece is important, but definitely controllable. Just like you mentioned NT, but this time with a smaller set of vendors to work with.