I runned a code formatter in our code base. Years later I was still 'blamed' for many things in our code as few files were untouched.
https://git-scm.com/docs/git-blame#Documentation/git-blame.t...
Once you move on from just banal issues like whitespace and move your way up to actual structural concepts in the code, ad-hoc starts completely falling apart (at least in my experience.)
I once encountered someone who did a giant re-formatting of code by rewriting past commits. Pretty disruptive for a day but did manage to keep history in-tact. Also, a little (or a lot?) dangerous...
It's usually called "blame previous revision".