Before people started reporting this type of problem, it was quite common for users to report that their game comments were being flooded with bots posting malware download links disguised as game updates.
I don't see these posts anymore, but I do see many complaints about being restricted. Therefore, it seems that Itch has implemented some kind of automated filter that, in addition to stopping these bots, is generating false positives. To be clear, this is just a assumption.