My guess is that AI accelerators will have some difficult-to-modify persistent memory based on similar chips having it, but I'm not sure if it would be on the same die or not. I wrote more about how a firmware-based implementation of Offline Licensing might use H100 secure memory, clocks, and secure boot here: https://arxiv.org/abs/2404.18308 

I wouldn't be at all surprised if this is a post-hoc rationalization of the thing Sam wanted to do anyway

Altman’s recent fundraising for AI chip manufacturing would increase available AI compute. Is there a good reason for why someone worried about a compute overhang would be accelerating the development of AI chips? If not, I think that it being a post-hoc rationalization is a good explanation.