I think the answer to this can be found at How do you reopen a closed question?:
Editing the body of a question within five days of closure will
also add it to the Reopen Review queue, where people with the the
ability to cast reopen votes will assess it. A question can only be
added to the Reopen Review queue once per closure via editing,
and if it's edited, reviewers will be shown a diff view of the edit by
default. For this reason, you should make sure that any edits after
closure should make clear why the question should be reopened. If you
or someone else makes a minor edit and doesn't follow up with a more
major edit, reviewers may only see the minor edit and thus disagree
with reopening, which may force you to resort to the next option [which is Requesting on meta to reopen].
which links through to:
Shog9 answered this question on meta.SO:
A question will only be enqueued once per closure via editing. It will be enqueued once per reopen vote as long as there are no outstanding reopen votes that've already triggered a review.
I conclude that if the question is edited after three Leave Closed votes, it will not return to the Reopen Votes review queue.