Yes, these decisions are being made by flesh-and-blood humans at the top of a social pyramid. Nick Land's deranged (and often racist) word-salad sci-fi fantasies tend to obfuscate that. If robots turn on their creators and wipe out humanity then whatever remains wouldn't be a class society or a market economy of humans any more, hence no longer the social system known as capitalism by any common definition.
If there is more than one AI remaining, they will have some sort of an economy between them.