"We're shutting down our repository"
I'm going to play 'wait and see' for now. My business does not require github (or anything like it) for success. However, it's probably an enhancement. A lot of open source code projects will remain, at least for a while. I'll wait and see where they end up, since I'd probably need to do pull requests on THAT system anyway if I wanted to submit anything.
Then I'll probably leave my stuff 'as-is' (for now) on github, and make them a "clone" of the _REAL_ repository "elsewhere" [sort of what I had done with stuff I had on sourceforge], continue to update it, and so on.
THEN, if things become 'really heinous', I'll dump my 'clone' repos [since they won't be "the official site"] and say 'why' on the MAIN site.
In any case, no need to 'rage-quit'. Not yet. Wait and see. And watch my ass.