I don't think they were "extending" Asahi, they were trying to hijack the project by making a new fork unrelated to their work, that's not the same, GPLv2 would force people to give attribution and not able to at least take the code without doing anything else for it, as you'd need to also have your own forks open source, that's more restrictive than MIT

Yes, but aside from the trademark issue (the fork cant call itself Asahi), GPL is 100% on board with letting you fork. It's on the tin, part of the freedoms it guarantees.