I don't think that Knuth dismisses it in the sense of a judgement on its values, but rather in the sense that this is not relevant to his work at hand and consequentely distracting from it, however interesting it might be. Knuth seems to be willing and able to push everything from his (work) life which isn't contributing to the tasks he intends to achieve. So while the conversation did trigger some thoughts of his about the topic to the point where he collected the 20 questions, he did so while biking and didn't even sit down with ChatGPT himself - probably knowing what a rabbit hole this could become. Instead he hands them over to a grad student to do so any only reviewed the results. Which seemed to have satisfied all of his curiosity at that point. Probably again, because he certainly knows how much time it would take to go any deeper on the topic.

It is faszinating to see how people manage to focus onto the direct field of work like he does. It is probably essential to be able to achieve what he did. And it is certainly important now considering how few productive years he might have left.