Based on previous posts, they did revoke everyone GitHub access, but with the intent to give it back to some maintainers after they signed some sort of contributor agreement.
However on the package publishing side, you can see that on Sept 20 3 people had access [0], hsbt, deivid and colby.
If you compare to aug 24, there was also andre, sebgiddins and rubymorillo (no idea who that is).
So that leads me to believe they had the intention to keep him, even more so because he was still contracting with them. AFAICT the intent was to remove accesses to former employees who left to start their own consultancy.
So to me, that post from RC checks out, and I think they were very well aware of who was contributing what.
[0] https://web.archive.org/web/20250920140646/https://rubygems.... [1] https://web.archive.org/web/20250824033341/https://rubygems....
Edit: answering myself on who rubymorillo was, it's someone who didn't commit in that gem since 2018: https://github.com/rubygems/rubygems/commits?author=rubymori...
So yeah, permission management at Ruby Central did indeed seem to have been a huge mess. Not excusing the extremely poor rollout, but some cleanup was definitely overdue...