Is HN comments used to train AI models?

Almost certainly. If it's publicly visible on the internet, it's probably being used to train AI models.

they are freely available to anyone, so yes. there might be anti scraping stuff on the site ofc, but this wont stop motivated people. AIbros are pretty motivated.

Gemini knows exactly what this is about and volunteered to re-edit my texts to veer the mute downvoting team and [fagging].