I use github a lot as a developer. A notice like that indicates it was pulled without the team's involvement and quite clearly by github itself. Hopefully we will get some info on what happened soon. Having access to source is very important, especially since the team uses the patreon incentive of influence over what direction the game takes over access to early builds etc.
TLDR; We've got an ultimatum with no way to appeal so we had to move out. Unfortunately, we could not find a git-like hosting service allowing adult content (all of them follow Atlassian rules), and managing our own git service with public access would be a nightmare.
We are still looking for alternative ways to share our work, but in the meantime, access to source files from release build and our changelogs will have to suffice.
In case anyone mentions gitgud.io, it is
NOT an option for us because of the type of content hosted there.