Large proportions of the supposedly human-produced content on the internet are actually generated by artificial intelligence networks in conjunction with paid secret media influencers in order to manufacture consumers for an increasing range of newly-normalised cultural products.
The social, mass-manipulation, consumerism part is already a reality. Mass-surveillance and manipulation by the government and private interests already exists. This will get worse. If a tool is at their disposal and furthers their ends, they will use it. If AI-generated content fulfills these criteria -- which I think it does--, it will be used like this.
The technical assertion part is better regarded as a prophecy. AI-generated content will be used more broadly once it gets better, faster, and cheaper. We'll have philosophical "content-creator" zombies. They will be indistinguishable from human content-creators.
You will have software where you enter personality traits, likes, dislikes, topics, and whatnot, and the software will run a Twitter account autonomously: tweets, replies, media, and all. No human required.