This well-researched question about the impacts of Brexit on travel was recently closed, apparently on the grounds that the best answer to the question is not immediately available at the time the question is asked.
The closure means nobody should be allowed to answer this question (or one closed as a duplicate of this) in the future, which does not seem appropriate. There is also a "Post is related to a rapidly changing event" tag (example here) which could be applied to Brexit questions, but apparently closure is better?
By contrast, here is a similar and very well-received question about visas (which the one in question was distinguished from), with similar motivation:
Unlike British politicians, I like to plan ahead and be prepared. If I am going to need a Schengen visa, I want to assemble the documentation early next year, so I can apply to the appropriate country as soon as I have an itinerary and it is at most 90 days before travel. Given how things are going, I am preparing for a hard, no-agreement, Brexit.
I looked at that question when writing the now-closed one and it led me to believe such questions were on-topic.
The accepted answer notes:
This answer is accurate at the time of writing. Any country might suddenly close their borders after you book but before you travel. That is a risk that always exists for future travel.
It seems like such questions and answers were once regarded as potentially valuable, but maybe should now be closed, because nobody currently knows just what will happen and the situation might change in the future, and there is no point in attempting to prepare for the future assuming no change from the present trajectory.
There are currently 1320 questions with the brexit tag, 612 of which are closed.
Should the rest all be closed for consistency, as such questions do not appear welcome here?
If not, what is the relevant decision rule which should apply?
As the closed question has been automatically deleted, here is a summary per request.
The question title was
"How will Brexit affect flight transits through the UK/London?"
It stated in bold, This question is not about traveler visas. It gave some brief background and stated "For the purpose of this question, assume the status quo trajectory" which at the time of the question (and still as of this edit on the meta question) is "no-deal Brexit" which might might affect the availability of aircraft/fuel/supplies/etc. to enter the UK on inbound flights from the EU and then be available for the connecting departure. The question summary asked:
Assuming status quo trajectory as of the time an Answer is posted/updated, how will Brexit affect flight transits through the UK currently scheduled for shortly after Brexit? Recognizing exclusions in travel insurance policies, are there effective ways to insure against/mitigate these negative outcomes?
The end of the question also stated:
This question will remain open to new answers without an Accepted Answer until after Brexit, inviting good answers especially citing authoritative sources for upvotes earlier.
Comments on the question basically said "it's not possible to know exactly what's actually going to happen or what deal will be negotiated, and any answer would likely involve speculation, so the question should be closed and never answerable by anybody. It's also not worth it for anybody to even try to prepare for travel that may be affected, except to just avoid travel. VTC."
It was a well-researched question citing sources from relevant government, media, and airlines about how they are/aren't preparing, and what rules might apply or be relevant. The nontrivial number of hours it took to prepare turned out to be a waste of effort which could not help anybody.
Yet, other brexit questions (which are lower quality according to guides of how to ask a good question) are staying open and even making it onto our HNQ list; the inconsistency is prompting this meta thread. Clarity of what is in and out of scope is helpful for a site. It's rather frustrating and discouraging of constructive contributions when there is a lot of inconsistency and caprice regarding what is and is not allowed.