The TSA has an irrational mindset that bags suddenly become highly unstable and might detonate at any moment once something is "found" and I don't see that ridiculous SOP changing. As soon as something "suspicious" is seen on the screen or the ETD, the SOP is to clear everyone away. Just like this week's LAX T-2 incident with fake novelty mortar rounds.
Doesn't matter that the odds of something actually exploding are too small to bother calculating - the "think of the children" and "anything is ok if it keeps us safe from (nonexistent) bombs" crowd will preach "safety" over sanity and rational response.