The crux here is the definition of AGI. The author seems to say that only an endgame, perfect information processing system is AGI. But that definition is too strict because we might develop something that is very far from perfect but which still feels enough like AGI to call it that.
Thats like calling a cupboard a fridge cuz you can keep food in it. The paper clearly sets out to try and prove that the ideal definition of AGI is practically impossible.
We already have much easier proofs that no system is perfect. So if it's only trying to disprove perfect AGI, it's both clickbait and redundant.