I had recently flagged this question asking to identify a soundtrack used by Jincheng Zhang for closure because the linked video has been deleted and this makes the question obsolete. This is the only post by the OP, who has not returned to the site since receiving an answer from @Bebs. In particular, they have not responded to the comments mentioning that the link to the video is dead, and it appears unlikely that they will do so.
My flag was marked as helpful but the post had not been closed, so I checked the timeline of the post and saw that the close review has been marked as "invalidated".
Can someone explain to me what it means for it to be "invalidated"? In the review queue, I see that there is one event, namely that @Bebs marked the question for closure on April 1. Then, the close review was closed on April 6 as "invalidated". Does this mean that no one else reviewed this item so it expired from the queue?
(Please note that I do not yet have the reputation to go through the review queues myself, I can only flag posts for action.)
On the same topic, I'd like to request that the question under discussion be closed as well as deleted, because it is obsolete. (Action taken by @Dom.)
After posting this question, I went through all my off-topic flags that were marked helpful with the question remaining open. By checking the timelines, I usually found the close vote to be "invalidated" or I did not find an entry for the review queue in the timeline at all: