My guess is they wanted to share some ideas; as in: what features could be added and what would an example implementation look like. They have no interest in deeper discussions or in forking the project.
To me a large PR with a disclaimer that it should not be merged seems a decent way of doing this and better than not sharing anything at all.
But I see how this could get distracting if more people do this. I assume this is a one time thing. In future I would recommend creating some fork with a note that it is not going to be maintained.
It just seems overwhelming and, therefore, very unlikely to get any traction. But I guess we’ll see.
Better if the submitter opened a feature request clearly describing the feature. As part of such a request, they could provide some screenshots and maybe a link to their AI-slop generated code for anyone curious to demo as a proof-of-concept, but without burdening any human with having to look at the slop.