I think it's a hard problem. The semanticscholar folks are doing the sort of work that would allow them to track this; I wonder if they've thought about it.

A somewhat-related parable: I once worked in a larger lab with several subteams submitting to the same conference. Sometimes the work we did was related, so we both cited each other's paper which was also under review at the same venue. (These were flavor citations in the "related work" section for completeness, not material to our arguments.) In the review copy, the reference lists the other paper as written by "anonymous (also under review at XXXX2025)," also emphasized by a footnote to explain the situation to reviewers. When it came time to submit the camera-ready copy, we either removed the anonymization or replaced it with an arxiv link if the other team's paper got rejected. :-) I doubt this practice improved either paper's chances of getting accepted.

Are these the sorts of citation rings you're talking about? If authors misrepresented the work as if it were accepted, or pretended it was published last year or something, I'd agree with you, but it's not too uncommon in my area for well-connected authors to cite manuscripts in process. I don't think it's a problem as long as they don't lean on them.