Your "meta-Turing Test" is rigged. There are 8 billion humans on this planet, statistically someone is bound to be able to distinguish AI from a human with near-100% accuracy across a reasonable amount of rounds through sheer chance.

Existence is too strong a criterion. Even correcting for random chance, if there's 1, 10, 100, even 1 000 000 examiners who could distinguish an AI from a human with high probability, that steal means the AI passed the test in practice, because even a million examiners is still a rounding error compared to the human population.