Cause in the opposite direction may be more fundamental, though in evolution all cause is circular. Because the world is variable a necessary adaptation in every lineage is a corresponding variability in each of its systems, subject to homeostasis. Combinations of this variability may then happen to offer survival of new challenges. So yes specific diversity is selected but it's because general diversity has been there from the beginning.

The article doesn't address this second-order effect of innovation. Instead it seems to take a basic result of evolutionary game theory and cast it in a model from physics.