It's clear that whatever tests he writes cover well established and understood concepts.
This is where I believe people are missing the point. GPT4 is not a general intelligence. It is a highly overfit model, but it's overfit to literally every piece of human knowledge.
Language is humanities way of modelling real world concepts. So GPT is able to leverage the relationships we create through our language to real world concepts. It's just learned all language up until today.
It's an incredible knowledge retrieval machine. It can even mimick how our language is used to conduct reasoning very well.
It can't do this efficiently, nor can it actually stumble upon a new insight because it's not being exposed in real time to the real world.
So, this professors 'new' test is not really new. It's just a test that fundamentally has already been modelled.