I can agree that C++ is so much better than Java, and would be an amazing move, but not in the form of Windows 10 Edition. Plus, PC is very different. You can't just expect people to move over to something else, so the question "How long till thats the only edition you can get for PC?" is irreverent since nobody can control what the people do on their PCs, even if Microsoft expected us to move versions. Just like the Fine Brothers, if they made that big of a decision, it would most definitely backfire. So you shouldn't worry about something like that.
(Sorry for the comment dupe. I forgot to quote, and I have no idea how to delete comments.)