I’ve just again come across a post where the answers didn’t seem to fit the question well, and a look in the edit history showed that the question had been substantially altered after the answers had been given.
As this is not the first time I’ve seen something like this, I wonder if there could be technical measures to prevent this.
Obviously blocking all edits after an answer has been posted would not be a good idea. It would block all possible improvements of the question, including those that don’t invalidate the answer.
If the distinction between large and small edits gets implemented, one might consider allowing only small edits after an answer was posted.
Another possible measure would be that the threshold above which edits no longer need review is higher for questions with answers, than it is for questions without answers. Possibly with a grace period, so that question edits generally don’t fail because someone posted an answer while the OP was already editing the question.