Author's edit right in on-hold question vs invalidating existing answers

Question

I asked this to get feedback on the community stance on whether the author is allowed to edit their (closed) question in such a way that it invalidates the existing answers.

Please read the related meta post in Worldbuilding.SE which led me to make this post.

Imagine this scenario: Alice asked a question. Bob read the question, and felt that it's too broad. However, he both answered and voted to close. The question was sent to the close review queue, where others reviewed it and it got closed. Then, Alice noticed that her question got closed, and edited the question to narrow the scope. In this process, Bob's answer became invalidated.

I agree that edits should not invalidate the existing answers. However, authors have full editing rights on their posts, and can make edits to salvage the question if it gets closed, so it gets pushed into the reopen review queue.

If Bob's answer become invalidated, I think he has brought it upon himself (unless he retracts the close vote). Even if Bob hasn't voted to close, he should know the risk for answering a question that is likely to be closed. If the question changed, he must make sure that his answer is still a valid answer to the updated question.

What does the community think of an author's edit to salvage the question, which then invalidates existing answer(s)?

Note: This question is more focused on how the community should handle the edit. Alice and Bob have done what they did, regardless of the breach of the etiquette.

Answer 1

Alice asked a question. Bob read the question, felt that it's too broad. However, he VTC and give an answer.

If Bob really believes that the question is too broad (or is closable for some other reason) then Bob should not have answered the question.

Answering off-topic questions, regardless of the motivation for doing so, encourages users to continue to ask off-topic question in the hope that they might get an answer.

The community closed the question. Then, Alice noticed their question closed, and edit the question to narrow the scope. In this process, Bob's answer become invalidated.

See above. Bob should not have answered an off-topic question.

If a question is not close worthy, I usually add the following comment:

Changing your question after you've received answers is inappropriate, as it invalidates the answers you've received. It can even make those answers wrong, and adversely affect the reputation of those who answered. If you now have a new or additional question, create a new post and ask it there; you can link back to this one if needed for reference.

This is a comment I often add to questions that have been radically changed after they have received answers. I then roll back the edits.

This, of course, does not apply to off-topic questions, which shouldn't have been asked or answered in the first place.

Answer 2

I think there's a big difference between "narrowing scope" and "completely rewriting the question".

If something is clearly off topic — Bob's clearly taking a risk (in terms of time, and potentially reputation) in answering, and that's fine. While it's odd to VTC and answer, maybe Bob's intrigued enough to take that risk and is clearly aware of it. If the question gets rescoped, and is good enough to reopen, the closure has certainly done its job. Bob was interested enough to answer, Bob can spend a little time to edit.

What's not fine is to write a completely unrelated question in order to get a question reopened — presumably to get out of a question ban. It's unfair to Bob (though Bob has the option of deleting) since it now looks like Bob's written an answer to a completely different question. Bob gets downvoted due to no fault of his own — and unlike with a narrowed question he cannot prune and edit his answer to fit as effectively.