I'd personally think that "report" refers to "game being against itch's guidelines", than using it as feedback to the host e.g. if a game isn't working? If a thread could summarize player's found results, it would be probably an alternate way, I guess?
Personally I don't think it matters as long as the moderators become aware of it. That being said, it only makes sense to do so if it actually violates a rule. And if it does not I would also like to hear from admins or moderators what their opinion is on the subject. After all, wouldn't a cleaner result list benefit everyone?