The interesting shift isn't that Microsoft ships Linux anymore—it's that almost nobody is surprised by it.

It is clear that UNIX won the server room, and the current form most people use of it is Linux, because POSIX ends up being a bit meh.

Additionally, it is a kind of phyrric victory, because when using cloud services with managed containers, the underlying OS isn't that much relevant, unless using languages like C and C++, without rich runtimes that abstract the OS.