My concern would be that if it can't produce accurate results on a random noise test, then how do we trust that it actually produces accurate results (as opposed to merely plausible results) on normal images?

Multilevel fractal noise specifically would give an indication of how fine you can go.

"Accurate results" gets you into the "what even is a photo" territory. Do today's cameras, with their huge technology stack, produce accurate results? With sharpening and color correction and all of that, probably not.

I agree that measuring against such a test would be interesting, but I'm not sure it's possible or desirable for any camera tech to produce an objectively "true" pixel by pixel value. This new approach may fail/cheat in different ways, which is interesting but not disqualifying to me.