You said it yourself before, if an Expert+ doesn't re-tag something as they see it, it doesn't need to be re-tagged. I report thread for tagging seems like a waste of time. If it's only slightly irrelevant, there's no real need to , and Experts+ are constantly on almost all the time. If they missed something, it's probably because of their laziness. Most people won't care if a tags wrong, so they probably won't try to report it either.
Anyway, could be subject to opinion. A tag that someone might find useless could have simply misunderstood, and the tag was actually correct, or at least correct to the person using it for their purposes.