You said earlier that we don't allow LLM-generated content on HN itself (i.e., the comments). So, at least in principle, that's already taken care of through exclusion.

If you mean the linked content: can come from anyone and anywhere--it's just whatever someone submits and is deemed good enough by The Algorithm to get attention. So that's not "HN content" - the content exists independently of HN. As for that, I'll repeat myself: the scientific community has managed somehow to intercommunicate for centuries despite language barriers before LLMs existed. (English was neither Einstein's nor Madame Curie's first language.) It's an existence proof that LLMs aren't needed to overcome those barriers.