Reminds me of rebasing Git branches in order to clean up commit histories, or rewriting Git repositories in order to change usernames/emails stored inside.

I just hope that whatever systems get created (bitemporal history, version control, etc.) have support for "replacing" previous usernames, or deleting events prior to a specific "record time" and replacing them with newer understandings of history. Doing so in Git (a more-or-less append-only system) results in multiple histories which diverge at the moment of the change.