It already went through the review. IIRC at the time when I cast my vote, there were already some off-topic close votes.
If you agree with my assessment that it is a duplicate, then it probably should be closed. (Although the close reason which will be shown will probably be off-topic, because that is what was chosen by the majority.)
@MartinSleziak Dupe-hammers can do it too, if memory serves. Whenever a user can close a question alone [for the chosen reason], the reason that user chooses trumps majority. I think. I'm too lazy to search Über Meta to check now.
It seems very probable. dupehammer usually behaves in the same way as the casting vote by a moderator.
In any case, I am very far from having a possibility to use dupehammer.
And I would be even a bit afraid of such special privilege. With great power comes great responsibility.
By which I mean that I would probably have to be a bit more careful in casting duplicate votes than now. Since now my vote can be easily invalidated by other users if I make a mistake. With dupehammer, this would be a bit more difficult.
@MartinSleziak Well, if one mistakenly closes a question with the dupehammer, on the one hand, still five users can rectify that mistake. Or one user with the dupehammer suffices, could be the hammerer themselves.
But one only gets the hammer with a gold tag-badge, and usually, one is then somewhat competent in judging whether a question in that field is indeed a duplicate.
Should this be undeleted? Not a big loss, but a reasonable question with a decent answer: OP deleted after getting the answer math.stackexchange.com/q/1455064