Thank you for your thoughts. Complexity and Disorder (Entropy) are two different but related ideas. One (Complexity) is not a "sign" of the other (Entropy). Homogeneity is a sign of Order, but of least Complexity. A growth in Disorder is necessary for Complexity to arise. If the system is in a state of equilibrium - nothing much happens and it's devoid of all complexity, but it's disorder is at its highest.

I agree our current understanding of Emergence is in its infancy and explanations are "after the fact". Our physical laws don't explain how complexity can arise in systems obeying simple rules (between its constituents). Novelty is unpredictable. But what is predictable is simply that Complexity can arise with increase in disorder.