I noticed that the question 'Isomorphism class of the zero module is not a set' on Mathematics SE was removed from the HNQ by a moderator, but curiously there is no entry in the timeline for when it entered the HNQ.
I went through the following related posts here on Meta SE, and it seems that the tool to remove a question from the HNQ is activated once a question has entered the HNQ at least once, and remains activated for up to 72 hours:
- rob's answer to 'Updating the Hot Network Questions List - now with a bit more network and a little less "hotness"!'
- user437611's answer to 'Why was this question manually removed from Hot Network Questions despite already being closed?'
But, can it also be used to pre-emptively remove a question from the HNQ? If not, why is there no event created in the timeline of the linked post on Mathematics for when it entered the HNQ?
Perhaps I should add that I am aware that certain other restrictions also prevent a question from reaching the HNQ (or kick it out if it's already there), such as MathJax in the title, or closure. So, while I chose a broad title for this post, perhaps unwisely, my interest is in how the moderator tool for removing a post from the HNQ was able to be used without it entering the HNQ in the first place, apparently.