From the looks of the screenshots it already appears that the Route numbers are starting over again. If that were to happen, confusing the Routes of Unova and Kalos would be pretty easy. Plus, I doubt that they want to redevelop a region that they've already made four games for AGAIN just to revisit it. The graphics were barely changed between RBY and GSC (outside of color), so it was pretty easy to just redo the maps. Now that we have an entirely different game engine it'd take much more effort. We've already been there twice, do we need it a third time?