"They have found a simple explanation for the observed fact the universe on large scales looks the same to us left and right, up and down -- a seemingly obvious and natural condition -- that in fact has defied explanation for decades."
In my unlearned mind this seems naive. We are observing the universe from a particular point in it, sort of like the blind men and the elephant, so how may we assume that the view is the same from everywhere?
Theory, yes. Observed, no. Cosmological theories depend on the axiom that the universe is isomorphic at large scales. But astronomers keep finding bigger and bigger structures: galactic clusters, superclusters, super-superclusters. And voids -- regions 100MLY wide that are almost totally empty.
The author is working from old assumptions and outdated theories.
That would be an extrapolation, but that the universe looks roughly the same in every direction from here deserves consideration.