I don't really think this is necessarily true. If the number of people who have jobs that can be worked remotely continues to increase, and if the possibilities of virtual office space can be realized than cities might become less appealing.

The main draw of cities is higher wages and greater social activity, but these are things that are decreasingly necessary to do in person, especially as VR adoption increases. As it becomes more possible to work and socialize online/in VR the incentives could shift so that it makes more sense for people to work online in high paying information worker jobs but paired with the low cost of living out in the countryside.

If this is the case it would be an interesting reversal of the current historical trend towards greater centralization, but this kind of decentralization wouldn't be unprecedented. I think you greatly overstate the extent to which rural America is doomed. If anything, it would seem that as economic opportunities become more evenly distributed over the globe due to the proliferation of information technology that people would come to prefer living rurally, especially since evidence suggests that people living in rural areas are happier on average[1].

[1] http://www.citylab.com/housing/2016/06/the-price-of-happines...