Linuxserver.io images don’t come directly from Docker Hub any more, and I don’t know if anyone noticed or cared. They use their own domain lscr.io that redirects to the Docker repository they’re using (currently Github) which makes it easy for them to move the repository without breaking things for users. https://www.linuxserver.io/blog/wrap-up-warm-for-the-winter

That approach is a good idea in general. If you’re running a medium to large size project, never directly rely on domain names you don’t control because it makes it painful to migrate to something else in the future. Even if your own domain just has a bunch of redirects (both URL redirects and email forwarding), it’s better than nothing.