What advantage would ever have Microsoft? Remember the Linux Kernel is under GPL. They would need to open so much it would become easier to run Windows software on other distro - actually killing many golden eggs chicken for MS.
My bet is Nadella will be shown the door well before... as soon as the board understands the damage he's doing to Windows because he can't take it's head out of the Azure hole. And once Windows no longer dominates at least one end point - the desktop one which is still the backbone of most businesses, Azure won't look a great solution to many.