I don't think they need to be voluntary to be pessimistic about the implication of the departures. It can be argued just as easily that so may high level execs being fired because of underperformance means OpenAI isn't achieving their goals. Revenue targets not being met is a large part of AI bubble promoters' thesis.

The article asserts that executives are leaving because they know OpenAI will fail and so their shares will be worthless soon. That’s a much more extreme read of the situation than the company simply being behind on some internal goals.