Yesterday I answered a question that had a given scope. Today I saw that the question had edits that changed its scope. I saw it because of a downvote to my answer - I believe it was due to my answer no longer being valid. It could even be flagged as NAA and I would agree.
This is not the first time it happens. I usually either edit my answers or let it be. I feel like applying a plain rollback would be authoritary and not nice to new users. I strongly believe that newcomers don't do such edits with bad intentions - they just haven't learned how things work here.
However, this situation keeps happening. It's only a matter of time until another edit invalidates someone's answer.
I am aware if these previous questions in meta:
But they mention nothing about rollbacks.
Should we have a procedure then? Something along the lines of rolling back edits that would invalidate answers, but also leaving comments about why the rollback was done, asking them to open up a new, different question with whatever new parameters, and point them to the sandbox?
I don't intend to do anything about the question edit I've mentioned - it has already gathered an answer within its new premises, so a rollback now would be more harm than good. I am asking for future cases.