@YemonChoi no, it was never closed. -- You can see this in the timeline, which is now linked to below the vote score.

@TimothyChow Having a rule does not mean it always needs to be enforced -- it just means that one can refer to it when there is need. -- So there would be exactly zero additional burden of 'policing', but just an additional means to resolve conflicts.

Why not just implement the simple rule that the user name should either be the real name or a pseudonym which can neither be confused with a real name nor is likely to offend anyone or to spark controversy?

@GerhardPaseman Maybe you didn't take daylight saving time into account?

If we take the posting of Question Number 1 as a basis, the posting of this comment marks a little more precisely the 10th anniversary of MathOverflow!

Well, Todd -- such things can happen, and actually there is not much lost by that. -- Since (in contrast to close-/reopen votes) a user can immediately cast another delete vote after a thread has been undeleted, to undo that small mistake, it would suffice to undelete the question to restart the decision process. -- Then the people who voted to delete can vote to delete again, and once the question is deleted, others can vote to undelete if they wish so. -- Or are there any issues with this approach which I don't see?

@ToddTrimble I'd just like to point out that there are no "don't delete"-votes, and that we cannot know how many people would have voted in that direction if that possibility would exist. -- So without the possibility to vote for undeletion at least after the thread had been deleted, I'm not sure how deletion can be seen as a democratic decision of the community here(?)

@ToddTrimble: I'd like to point out that since a moderator has cast the final vote to delete, regular users cannot vote to undelete. Also let me point out that at the time the final vote to delete was cast, the question had 4 pending votes to reopen.

@GerryMyerson Indeed. -- And I think the combination of closing a question as "opinion-based" and taking concrete actions on the basis of it or triggered by it seems particularly weird ... .

As to @YCor's recent edit -- googling and searching on zbMATH, I cannot find evidence that there is a mathematician named Denis Chaperon de Lauzières at all.

@CarloBeenakker Dropbox, inc. being a company with a market valuation well in the billion-dollar-range, I'd have been surprised if they would have made such exception -- companies of that size tend to act somewhat similar to authorities. At least you would need to convince them that making the suggested exception would yield sufficient positive- or not making it would yield sufficient negative publicity for them.

Whatever one might answer to this question -- I think first of all, it raises the meta-question why someone who has never answered a question or got an answer to a question they asked on this site so far is interested in knowing this. -- In particular in view of this discussion.