As a materialist in matters of the mind, I regard proposition 2 to be an unverifiable belief of those who hold it, but I also regard proposition 1 as being simply a statement of how things currently are: at this point, we do not, in fact, know what intelligence is.
To say that it is "just" highly tuned patterned IO with the environment would be so broad as to be meaningless; all the explanation is being brushed away by that "just", and in the current state of research, no-one has either demonstrated AI or explained intelligence with sufficient specificity for this to be a clearly true synopsis of our knowledge.
You are not quite, however, asserting that to be so, you simply posed the question of whether it is so. In so doing, you are shifting the burden of proof, and proposition 1 stands until someone settles the issue by presenting a testable - and tested - theory of intelligence (note that I wrote of intelligence, not about intelligence; we have plenty of the latter that do not rise to the level of being the former.)
My attitude to the current crop of models is that they demonstrate something interesting about the predictability of everyday human language, but not enough to assume that simply more of the same (or something like it) will amount to AI - we seem to be missing some important parts of the puzzle. If a language model can come up with a response coherently explaining why I am mistaken in so thinking, then I will agree that AI has been achieved.