I'm taking this sudden change of heart as an admission that they don't have the ability to stop all those pornbots that have escalated from "my pussy in bio" to just showing us AI pussies in replies.
Stopping the Pornbots would mean having a dedicated trust and safety team, which I’m pretty sure were the first people shown the door.
Alternatively, if they ban the porn bots the user metrics probably look atrocious and we all know the number can never go down.