When you rewrite a book and create a new edition, you don't typically recall the old editions. A rewrite needn't be destructive.
My point is that git says "rebase" even when the underlying base of the commits affected is not changing. This is an artifact of the UI, since the command to rewrite in git is typically git rebase -i.
rebase doesn't mean "rewrite commits", it means "create new commits based on these ones, based of a new base". Your original commits are still there, and are pushed to the remote, but are GCed after a certain period (default 30 days?) if they are not referenced from anywhere. Since unreferenced commits are pushed to the remote, you can easily restore those commits within the GC period.