That's a useful thing to remember! Thanks for pointing it out.

Anyway that's the broad picture of the supposed rivalry which might motivate the perceived 'defiance' of Canonical, and the sense that parts of Ubuntu's stack are 'downstream' from Red Hat or Fedora.

Idk if the characterization really makes sense, but that's what the earlier commenter was talking about, not a proper upstream in terms of distro tooling or repositories.