We have at least one question ( https://gaming.stackexchange.com/questions/1184/dosbox-abandonware-games-where-to-find-closed ) which was flagged as a duplicate of another question, and then that other question was removed for moderation. For consistency, we should either unflag as a duplicate, or close this question as well?
It depends why the second question was deleted. If both questions are equally guilty of whatever it was that caused that deletion, then both should go. If the "dupe" is in the clear, then it should be re-opened.