Sam Altman spoke at an APEC panel on behalf of OpenAI literally yesterday: https://twitter.com/LondonBreed/status/1725318771454456208
I don't know the guy but nothing can really be assumed about this.
All kinds of reasons.
The biggest risk for OpenAI is the public perception that the discretion of ChatGPT can not be trusted. If the CEO is caught using poor discretion, the public will transfer that property to the company's products.
For instance, if Tesla could fire Elon Musk, I'm sure they would have by now.