Out of curiosity, why don't you make "YC churn" announcements read-only, like job ads are?
There's not really much curious conversation when they happen, and not really a huge chance of it, either. As an example, the announcement of sama taking over was a hundred and fifty comments of almost exclusively "Congratulations!"
They're posts that are almost exclusively doomed, either to incurious compliments, insults, or needless pessimism; what questions that are asked usually don't get answered, so there wouldn't really be a loss in it anyway.
I wouldn't call this a "churn announcement" - it's the biggest YC news in years. I guess I can think of a few different answers to your question. One is that since it's significant new information, it's on topic (job ads are the opposite of that). Another is that there's a special relationship between YC and the HN community, and it's good for the community to have space to discuss that. A third is that there is definitely no way that the community would support us trying to close such a topic to comments.
Also, job ads get placed on the front page by software. This submission got on the front page by upvotes like any other.
It's definitely newsworthy and relevant to the community. I support the status quo of non interference (laissez-faire) by the mods into publishing status of this news story and your reasoning stated in this comment.
There's not really much curious conversation when they happen, and not really a huge chance of it, either. As an example, the announcement of sama taking over was a hundred and fifty comments of almost exclusively "Congratulations!"
They're posts that are almost exclusively doomed, either to incurious compliments, insults, or needless pessimism; what questions that are asked usually don't get answered, so there wouldn't really be a loss in it anyway.