I see Copilot as a trial balloon. If they get away with it you can expect the next move to appropriate the body of open source that is GitHub. Why the archenemy of open source should suddenly be trusted to play nice is something I really can't grasp.
It's not sudden - they've owned it for a while now.
What I can't understand is people feel locked into Github because of the social features. To me they seem the least important part of Github, particularly with so many OSS projects running communities on Discord or Slack.