The statement about Sam on the announcement post at https://www.ycombinator.com/blog/updates-from-yc/ evolved over time:

1. March 2019: "Sam is transitioning to Chairman of YC and has shifted his operational responsibilities at YC to other partners. This change will allow Sam to spend more time focusing on OpenAI while still being responsible, along with the rest of the partnership, for the long-term social and economic success of YC. Because YC is run as a partnership, there will be no significant operational change."

2. June 2020: "In May 2019, Geoff Ralston took over as YC President. At that time, Sam Altman stepped away from any formal position at YC."

3. April 2021: gone entirely

waybackmachine: https://web.archive.org/web/20190310003417/https://blog.ycom...

Basically seems like they were updating it as leadership turnover happened as Sam went from president to chair to out, and Geoff from partner to president to out.

I'm pretty sure the HN thread hasn't changed, but you're right, the YC post has: https://web.archive.org/web/20190310042303/https://blog.ycom.... One could bisect to find out where. Weird! I've never known these things to change like that, and it's not as if the news wasn't already public.

Nor in 2022 when it was first archived by Wayback (unless archives from previous have been removed)

https://web.archive.org/web/20230000000000*/https://www.ycom...

Thank you for the article, I saw a comment from Sam in the HN post but agreed it did not look obvious that he got fired.