It seems like Microsoft has pivoted to be a cloud, services, and dev tools company. They no longer expect revenue growth from Windows. In that context the best strategy is open-source and support everything.... Exactly what they seem to be doing.
I'm not so sure about that. I think Microsoft have realised finally that competition is good, and actually you can make a lot of money out of services. If you extinguish competition, then you can't sell so many services.
At least, I hope that's what they have realised :-)
No matter what good you believe you're doing, it's just in the end going to be used to extinguish competition.