Apologies if I'm being dumb, but I'm confused. I assumed "adopted" implied that Code Shelter has some alternative repo that it (Code Shelter's community) is maintaining. Is that not the case? If not, then why list it at all?
No, "adopted" means that you gave Code Shelter permission to add contributors to your repo (the same repo you've always used). Otherwise, there wouldn't be a need for CS, since anyone can fork any repo.
CS is there to ensure continuity for the original repo (and releases).
CS is there to ensure continuity for the original repo (and releases).