Earlier quoted context omitted.
When the repo goes private, people who can’t see it any more can’t have it in their list of starred repos.
Why not? I think the respectful solution is to show it as "you starred X, it's private now, you can unstar if you like" (make sure if the name changes privately then the new name isn't shown). Such a solution is not only good in the case of mistakes like this, it also doesn't gaslight the person that starred a repo only for it to disappear from their list.
If I publish something and you save the link and then I decide “nah, I don’t want that to be published”, I haven’t gaslit you.