The thing with Linda is that while she's theoretically the boss, and Musk reports to her as CTO/CPO everybody knows that Musk is the boss and she's there to... sell ads? Actually I don't know what she's supposed to do, but it doesn't matter, she's certainly not allowed to touch either the product or the technology and Musk can fire her at any point as owner/chairman.

This, OTOH is a just a simple straightforward C-Suite. Sam is the boss, and he hired two reports to handle areas where they have expertise. This might be the simplest corporate thing OpenAI has ever done, lol.