But if I had to guess, I believe they'd argue that an LLM is basically all a priori knowledge. It is trained on a massive data set and all it can do once trained is reason from those initial axioms (they aren't really axioms, but whatever). While humans, and actually many other animals to a lesser extent, can make observations, challenge existing assumptions, generalize to solve problems, etc.
That's not exactly my definition of intelligence, but that might be what they were going for.