I think there seems to be a mismatch of terms involved. Ontological probability, or propensity, and epistemological probability, or uncertainty, are being confused. Reading over this discussion, I have seen claims that something called “chaotic randomness” is at work, where uncertainty results from chaotic systems because the results are so sensitive to initial conditions, but that’s not ontological probability at all.
The claim of the paper is that all actual randomness, and thus ontological probability, is a result of quantum decoherence and recoherence in both chaotic and simple systems. Uncertainty is uninvolved, though uncertainty in chaotic systems appears to be random.
That said, I believe the hypothesis is correct simply because it is the simplest explanation for randomness I’ve seen.
Chaotic classical simulations? Could you elaborate?