AI recommendations is something for bored people in my opinion. Sure, you may stumble upon content you would not have considered, but the examples people tend to bring up aren't too convincing.

Some might think that showing depressed people some cute dog pics would lighten them up, but that isn't how it works. On the contrary, the expectations towards themselves to be happy can be counterproductive.

I believe this is the crux of the matter, since social media tends to load people with expectations, depression or not and advertisers try to use this handle to promoted their products.

If a site would try to "transfer positive emotions" I would be seriously concerned. Humans don't even know what content would be best for an individual. How would you train an AI? From resonance of other users? No, that leaves out a lot of context.

But I still don't think AI curators should be regulated, because the quality of regulation would certainly be horrible.