Does he actually call for expropriation without compensation? That part just feels like people massively extrapolating from what he said.

The small snippet, no, you're correct, he doesn't call for expropriation, though on its own it does seem an odd thing to say.

The full podcast, no, you're correct, the interpretation folks make isn't reflected in the podcast itself.

In the full scope of what the public believes it knows about Sam Altman, from allegations of familial abuse, to the board fiasco, to the expropriation of art and other works by humans to train the frontier models with reckless abandon, one sees that the absolute cynicism by the public writ large regarding anything Mr. Altman does or says is probably appropriate.

Perhaps unfortunately for Mr. Altman, as is the case for most public figures, his statements aren't seen as encapsulated logic statements to be taken individually, but in the scope of his broader public persona.