I've seen with my own eyes what this study has talked about. And it seems to be accelerating.
The younger generation, despite the good show they put on about not following the materialistic ways of previous generations, are fully indoctrinated with pop culture, love the amenities, and the educated ones can't get to the burbs fast enough.
The drain in many rural areas is relentless and self perpetuating. Trump has really helped with reviving some of that by giving manufacturing a boost with his policies, but under the age of 50 what you have left of the younger generation is mostly the dregs except for a very small minority that just can't stand the big city.
It's the long term that worries me, especially with more automation on the horizon that ultimately is going to drastically reduce the middle class and the affluence of the very burbs everyone's flocking to.
If it plays out, we're heading toward a model of urban city-states, and vast rural areas of scattered population here and there with lots of nothing in between.