It's possible that they shut the line down earlier than park close (I remember that Disney did that with Flight of Passage when it first opened since lines were so long), but even if that were the case, I can't imagine that they'd shut it down all that far before park close. I can't actually remember a time when Universal has used that practice of shutting the line down early if i'm being honest.This sounds like a super smart idea because can’t they not kick you off the line until the entire line is emptied? Also do you think they will be running it all day or close it early because of crowds? I kinda want to try this now just so I’m not wasting my entire day.
However, if you are dead set on wanting to ride that day, I wouldn't risk it.