This might actually be intentional (though I don't think so, and if it is, I'd recommend changing it to only be this way for the moderators of that particular forum), but the "spam?" prefix now seems to show for every thread with a (the last?) post flagged, rather than only when the first post was flagged.
Example at this moment is "Crossing the Bering Strait" in the RTW forum, where only the 10th (and last) post is under review atm.
That was actually kind of on purpose - obviously mainly to benefit moderators though. I've fixed it now so it will only show that flag if there is an entry by the original poster that is flagged as spam (not just the first post). Partially because that ends up being a simpler query and partly because that would mostly be a fair flag to make.