Software is always more important than hardware. All the big players have access to NVIDIA chips today and yet only OpenAI has ChatGPT, proving the point.
OpenAI probably wishes someone would create competition to NVIDIA and this is Sam Altman trying to make that happen himself, since no one else seems to have been able to pull it off so far.
A conflict of interest would be OpenAI buying Altman's chips at inflated prices or something like that.
But if he makes a bunch of money selling OpenAI chips and OpenAI gets better/cheaper chips, that seems like pure win-win and totally free of ethical conflict.