>Heck, I could write awful things here on HN
Yet you don't (I assume), why?
If I were to guess, it's because you would be banned quite swiftly. It's a niche place after all, generally speaking, it's certainly no Facebook in terms of scale.
Unfortunately, if a place like HN is swamped with accounts and comments all going against that, yes AI is going to be used to automatically detect and remove some comments, as well as more strict requirements for account creation. As many other platforms have leaned towards. We're all operating off the basic premise we're not trying to be bad actors trying to ruin the experience for others. Once that premise no longer exists, say goodbye to most easily accessible platforms that can't afford AI moderation.
Now that's out of the way, the general problem with "AI saying awful things" isn't that in isolation. It's that people will then do things with what it's saying. Whether it's harming themselves, others, or even just spreading that "information". This isn't currently a problem because we still have proper checks, but as Google's terrible AI attempts have gone telling people to put glue in their pizza, some people are going to eventually stop checking AI and start believing it "Siri told me sharing my chocolate was healthy for my dogs".