It's perfectly fine, from a legal standpoint. My personal opinion regarding the ethics of the situation is mainly a reflection of that - in the bizarro world where social media companies need to synthesize content to drive wholesome engagement, it's entirely their right to do so. When you sign up for any of these services, you acknowledge that your uploaded content and online experience is completely subject to their will.
The ethics of all this have already blown over. Twitter and Facebook have both been proven to shadowban controversial figures, and no ethical panic ensued. People don't care, they want a Tik-Tok style feed of sugar water and sweet dreams fed to them on an IV drip. If the next step is fabricating fake content (again, considering how many real content creators exist this seems unlikely), then there is no ethical discussion. It's as fake as the AI-corrected profile-picture you shot on iPhone. It's as real as your approximate location being tracked by Walmart WiFi and then processed into shopping habit data to sell to competitors. If you use Facebook or Twitter (or arguably any social media) then you're already being manipulated. They don't need to promote fake content to make you think what they want.
