@JDShu: I understand your counter-arguments, but I just don't see that I have any skin in that game. I am not a developer, so I have no need to commit to X or Mir or Wayland. Kibbitzing in corporate politics goes on all the time but I'm out here in the peanut gallery, so it's a bit pointless. (Like football fans pretending to coach.) When a product is offered, I'll see if I like it. That's no different than the normal state of affairs. If I don't like Mir, I won't use Ubuntu. Nothing difficult there.
I do, though, agree that there's reason not to take this github post at face value. I've always assumed Canonical would get proprietary support for Mir only by paying for it. Maybe that's in the mix here.