The question you link to was closed as a duplicate by the Community ♦ user, which means that the OP themselves agreed it was a duplicate; see this announcement on main meta for when Community dupe-closures became a thing.
This is fine when the old question has an accepted answer but the new one doesn't, since by agreeing that it's a dupe the OP of the new question is essentially accepting an answer. (Some unanswered story-ID questions have even been closed this way in the past.)
However, in the example you link to, the new question has an accepted answer but the old one doesn't. This means that in the unlikely event that the current answer to the older question turns out to be incorrect and a different answer is posted and accepted, the dupe-closure will no longer be valid according to our policy. In view of this, I've reopened the question.