This is a classic case of a theory not being dead until all it's proponents kick the bucket.
“This finding is based on a false premise, that early dogs have to be phenotypically different than wolves. Dogs are wolves in the first place. There is no reason to assume there should be physical changes unless the dogs method of living changed.”
The Russian experiment involving the domestication of fox suggests that there are rapid physiological changes to canids when domestication begins to take hold. I’ve also read that genetically dogs & wolves are practically indistinguishable. Whatever is going on with the evolution of the dogs body type it is both rapid & genetically subtle.