Not to be pedantic, but this is actually incorrect, both under federal and California law. Case law is actually very explicit on the point that the information does NOT need to be previously unknown to qualify for whistleblower protection.
However, disclosing information to the media is not typically protected.
We can evaluate that argument without caring too much about whether the writer intended it, or whether some other circumstances might have forced their word-choice.
"The Mercury News and seven sister news outlets are among several newspapers, including the New York Times, to sue OpenAI in the past year."
That's a conflict of interest when it comes to objective reporting.
In this case I see very little reason to believe that would be the case. No one has hinted that this employee has more damning information than was already public knowledge, and the lawsuit that he was going to testify in is one in which the important facts are not in dispute. The question doesn't come down to what OpenAI did (they trained on copyrighted data) but what the law says about it (is training on copyrighted data fair use?).
I, of course, am not proposing that OpenAI assassinated this person. Just pointing out that disclosures of known information can and do motivate retaliation, and are considered whistleblowing.
Presumably you mean the company. How many decades before AI has that ability.
Since I wrote this the tone of the thread shifted and others took up the torch to focus on the tragedy. That's wonderful, but someone had to take the first step to stem the ignorant assassination takes.