It is the same as plagiarism since the one who posted it isn't the one who write it or who made it so it is possible to consider it as plagiarism although the data isn't taken from somewhere else so i'd say it is a partial plagiarism and not plagiarism at the same time. Since it is like that then it should just be considered as spam. Also, people would have to check it to see if it is AI generated or not at all. For punishment, I think restricting an account to post for a certain amount of time like unable to post for 1 day as an example.