You assume he revealed everything he knew, he was most likely under NDA, the ongoing lawsuit cited him as a source. Which presumably he didn't yet testify for and now he never will be able to. His (most likely ruled suicide inb4) death should also give pause to the other 11 on that list:
> He was among at least 12 people — many of them past or present OpenAI employees — the newspaper had named in court filings as having material helpful to their case, ahead of depositions.