I think the analogy is more like someone on the board + Executive Director of your wildlife preservation nonprofit buying up land with potentially endangered animals on the side, with the (presumed) intention of selling the land back to the nonprofit.
Clearly a COI even if it's net good for the animals.
Direct and immediate Conflicts of interest can arise if decisions you make for one company could regularly come into conflict with decisions you have to make for the other, example, if he was starting another AI company making rivals to ChatGPT. But in the case of the chip company, nobody has really made a persuasive case of how that would happen here. In terms of interrelatedness, maybe they would build chips customized for openAI. But that would be a potential benefit Open AI, not a conflict!
Suppose I am on the board of a wildlife preservation nonprofit, and I am thinking about starting a catering business, and talking to potential financial backers.
If you want to take it to the extreme, you could argue that I could award my catering company a lucrative contract to provide food for the nonprofits cafeteria. But that would be entirely speculative on your part. it would by no means justify immediately firing me from my position at the nonprofit. If you take those hypotheticals out far enough, you could basically argue anybody with any other job or role is potentially in conflict of interest. But again, doing that requires assuming a tremendous amount of bad faith.