Eh. Their messaging is immature here, but you don't need to be on the biggest thing - especially when you have a limited set of contributiors, not millions.

It is deeply unfortunate that Git won instead of Mercurial and even more unfortunate that GitHub won. GitHub's code review/PR UI is an abomination. We had better tools 15 years ago and GitHub is still a regression. There are tons of reasons to move off it if you're willing to pay the cost of working with alternatives.