A story that I think is clearly worth discussing on HN is "what seems to have happened with grok here?". Musk fiddling with the system prompt is only one of the possibilities. People here can make arguments for or against that theory or others.

But also, it's news worth discussing on a technology news discussion site if the owner of one of the largest technology platforms by reach is manipulating the information on that platform in a new way, even if there have been lots of other discussions about them manipulating things in other ways.

Notably, I think the only uninteresting threads here are the ones like this one that are questioning why this is news. Yawn.

I'm guessing that your view aligns with the theory that novelty is one of the more important measures of a HN post. In other words, a topic that "is a very repetitive story that's been on HN a bunch" is not novel, so is less valuable on HN. In any case, whether that is your view or not (sorry if I misinterpreted you), I think this is too narrow a view. A topic can be one that has been on HN a lot, but still be novel, interesting, fresh if the new story has some different twist or nuance to it. Also, not everyone reads HN to the same degree, so what is "very repetitive" to one set of readers may not be to another. I know that some users flag certain posts (and mods do not subsequently unflag them, even on appeal) because of their perception of a post's lack of novelty, but this seems overly censorial when these users could skip reading it, not upvote it, etc.