Comment by Vegenoid
This is an interesting question, but it seems at least possible that as long as the fundamental operation is simply "generate tokens", that it can't go beyond being just a form of next-token prediction. I don't think people were thinking of human thought as a stream of tokens until LLMs came along. This isn't a very well-formed idea, but we may require an AI for which "generating tokens" is just one subsystem of a larger system, rather than the only form of output and interaction.
But that means any AI that just talks to you can't be AI by definition. No matter how decisively the AI passes the Turing test, it doesn't matter. It could converse with the top expert in any field as an equal, solve any problem you ask it to solve in math or physics, write stunningly original philosophy papers, or gather evidence from a variety of sources, evaluate them, and reach defensible conclusions. It's all just generating tokens.
Historically, a computer with these sorts of capabilities has always been considered true AI, going back to Alan Turing. Also of course including all sorts of science fiction, from recent movies like Her to older examples like Moon Is A Harsh Mistress.