Microsoft will do whats best for them.
Temporary this includes embrace open source to some degree and being reasonable nice to Linux. For example WSL can help with trying out Linux and help cross platform devs on Windows to develop for Linux which can help with a to Linux migration. But it removes the main reasons why a lot of students, scientists and server devs had to use it. So for now it's net-good for them, which can be good for Linux, too.
But what will happen if it again is more profitable for MS to not act nice?
How long will it then take to WSL to have features in a way which make it likely software only works on WSL Linux and maybe Azur servers but won't be available on normal distros.
How long until GitHub will have some small but very usefull features which happen to only be available in some Windows GitHub client pushing companies to require Windows first desktop systems?
How long until they will influence legislation around computer security in a way which have effects like being practical impossible for normal desktop Linux clients or require some proprietary Linux core component due to a combination of legislation and patents, which distributions for Azur or Google cloud surely will have for free, but the competition?
Honestly I hope so long that you could say never.
But I believe open source and free desktops are as much threatened by MS today as many years ago when people aware about it often treated MS as a evil company for good reasons. But today it's in a way more roundabout, very subtle very hard to pin down way. This gives them the chance to succeed where they failed before, but us the chance to both profit from them and while preventing them from succeeding. Optimally leading to some form of stalemate where both are profiting from each other.