You are posting this under a pseudonym. If you did publish something horrific or illegal, it would have been the responsibility of this web site to either censor your content, and/or identify you when asked by authorities. Which do you prefer?
You let people post what they will, and if the authorities get involved, cooperate with them. HN should not be preemptively monitoring all comments and making corporate moralistic judgments on what you wrote and censoring people who mention Mickey Mouse or post song lyrics or talk about hotwiring a car.
It seems reasonable to work with law enforcement if information provides details about a crime that took place in the real world. I am not sure what purpose censoring as a responsibility would serve? Who cares if someone writes a fictional horrific story? A site like this may choose to remove noise to keep the quality of the signal high, but preference and responsibility are not the same.
Censoring AI generation itself is very much like censoring your keyboard or text editor or IDE.
Edit: Of course, "literally everything is a tool", yada yada. You get what I mean. There is a meaningful difference between that translate our thoughts to a digital medium (keyboards) and tools that share those thoughts that others.
HN is the one doing the distribution, not the user. The latter is free to type whatever it wants, but it is not entitled to have HN distributes his words. Just like a publisher do not have to publish a book he doesn’t want to.