What are they going to extinguish, Linux? By letting people write C# code on Linux? Or are they going to extinguish Java? Or are you saying they'll extinguish Xamarin? If that's the case, that doesn't make since because Xamarin isn't a competitor.
Microsoft is so far from having the capability of doing any of those things. Any company that has a monopoly starts acting evil, but Microsoft is no longer close to having monopoly.