Here is one point to mindful of: discouraging such practices might drive potential new users away. A possible work around is to create a category for such and then just let them put the content there. This way the user feels they have contributed something of value, others can link to it if needed in other parts of the forum and users that are not interested in the AI post can skip the category and all of the links.
The posting of AI on user forums will be here going forward. I don’t see any norms for this within the next few years; similar to the question of the use of AI in formal education.
However with the new wave of AI, LLMs and diffusion, the only constant is change so my reply on this is not to be seen as something carved in stone or something that I might even agree with in the future.