I don't think using AI generator is plagiarism, but if the AI generator took someone text, then it's good since some people can report it to make these shitposters get banned.
I think any user especially merit source need to give merit to a post which have an emotion and a subject. Usually AI generated post are objective and only discuss about the particular matter. Although there are few users are tend to explain particular thing in very objective.
I think it would be more classifiable to be plagiarism than even spamming or shit posting because some of them are mostly talking on point. A BoT generated work isn’t yours and that is what plagiarism is all about.
It is hard to detect this accounts when distributing merit because the merits source might just focus on the content shared and how it was of help rather than having to dig into the post to self if it is Al generated. Also most emotional posts are just merit fishing posts or even fabricated lies.