Yeah, from what I've been able to gather the 3 year shift is going to happen in the next couple of years. Point being that even if all the PD's suddenly decided that integrated/combined models were far superior (no concensus on that, and there probably never will be!) and they wanted to get red of independent residencies, it would take years and years and years for it to happen.
But most if not all people in positions of power within PRS came from GS/ENT to plastics and they still feel that plastics should be an option for someone who has completed a surgical residency. I don't really see it shifting much more than 50-50 one way or the other for the foreseeable future; definitely not until integrated grads start infiltrating the traditional power structure of PRS.