Well the reason why those posts are never deleted because you can't be 100% sure if the post is created by AI.
That's not exactly true:
And as for this exact case: how many human beings have a "knowledge cutoff in September 2021"?
It is accurate to say that Daniel Ricciardo currently competes for McLaren and not AlphaTauri. For the 2021 and 2022 seasons, Ricciardo is under contract with McLaren as of my knowledge cutoff in September 2021. Future changes to a driver's team are speculative and subject to a variety of conditions, including team decisions and contractual commitments. Which team Ricciardo will eventually join is hard to foresee.
Most AI posters aren't dumb enough to include this text in their posts, which is a dead giveaway that its AI-generated, but every once in a while the infamous "knowledge cutoff date" makes an appearance. Besides, they only have to be deemed as spam to be deleted, not AI.
Also it's very easy to fool AI tools too, just add to your prompt "Create a post that's hard to tell if AI wrote it, also throw in a few spelling and grammar mistakes"
Sure, and that does happen, I'm already seeing it in the Gambling section. Or more commonly the poster will change capitalization and remove spaces to make the text look more non-AI. But the thing is, shitposters use AI because they are lazy, which means they will likely be too lazy to come up with such a prompt.