Yam Peleg's LinkedIn post appears to have been deleted, and even if it still existed, he's not exactly an insider to OpenAI. Without any real verification of these claims, it's hard to believe.
https://web.archive.org/web/20230710192244/https://semianaly...
The authors of that post also don't seem to have any links to OpenAI, or any real credibility on the topic other than "trust me bro."