That is crazy talk, Win32 is not going away for a long time. There are professionals who work and use Win32 programs everyday for like web design, developing code for software, video editing, Photoshop work, audio editing.
This one, bingo. If they killed off win32 and the applications that go with it, I'd have to migrate to Linux as a desktop. I would never use Windows again at that point. I have very little investment in it as it is except for the software ecosystem and ease-of-use. I'm sure the same is the case for the majority of developers out there. We'd go where the tools and ecosystems still exist.