I think there is multiple cases where repos are mirrored between Codeberg, GitHub and internal and public instances of Gitlab. People want to open issues where they are and they can get accounts. Also I had to migrate issues from one repo to the other. Having wikis moved to git repos is a big advantage over trac and redmine (we just recently moved old projects and it is a pain each time). So I highly welcome anyone who moves issue tracking to git as well.