Then don't need them to rewrite history? That's kind of on you and your own OCD at that point. If you are making them use a PR workflow anyway, become friends with git options like using --first-parent to shallowly traverse the DAG and let git's tools give you a clean view. (Or use GitHub's PR Squash options, if you really must rewrite history.)

Someone that does that isn't going to meaningfully rewrite the history anyway, just squash on merge.