I get why that is in practice different then the manner in which compilers are deterministic, but my point is the difference isnt because of determinism.
Create a program that reads from /dev/random (not urandom). It's not determistic.
In other words, it isn't the random number part of LLMs that make them seem like a black box and unpredictable, but rather the complexity of the underlying model. Even if you ran it in a deterministic way, I don't think people would suddenly feel more confident about the outputted code.