The kernel is just mirrored on GH, which is why they want PRs and bug reports sent to their mailing list.
And, with a whiff of irony, git itself.
Why is this ironic? Git predates github.
It's logical of course, but I see the irony. Or maybe it's not irony, nobody really knows what irony is, but it's mildly.. amusing? It makes half my face smile in a manner similar to but not quite like a smirk.
Is the Git project expected to uproot themselves and go chasing Github or Gitlab or Gogs or whatever else is fashionable?
Definitely not 'expected'. I like the mailing list bug tracking more than having that on git{hub,lab,whatever}.
git makes it even possible to host a repo on multiple git* hostings, but apparently nobody came up with a successful distributed pullreq/issue tracker yet.