I don't think that would work, because GPT doesn't actually comprehend anything. Comprehension requires deriving meaning, and GPT doesn't engage with meaning at all. It predicts which word is most likely to come next in a sequence, but that's it.
What I think we'd be more likely to end up with is something GPT-esque which, instead of simply generating text, transforms English to and from a symbolic logic language. This logic language would be able to encode actual knowledge and ideas, and it would be used by a separate, problem-solving AI which is capable of true logic and analysis—a true general AI.
The real question, IMO, is if we're even capable of producing enough training data to take such a problem-solving AI to a serious level of intelligence. Scenarios that require genuine intelligence to solve likely require genuine intelligence to create, and we'd need a lot of them.