I doubt they really mean it, generative AI content is a true boon for social media companies, an endless stream of "weird" quirky content for people to click on.
Young and savvy people will uninstall Instagram and TikTok if the apps get infested. Trend setting teenage girls are interested in watching humans talking, not in watching Beeple videos.
I bet that most people (even tech-savy) can't reliably differentiate real content from AI content. Instagram and Threads for example are already full of AI content and AI "models".