Nope, i'm pretty certain it's the actual ingame map of the region and thus with the shape it kinda gives off a balanced yin-yang type feel much like the game seems to be pointing towards so far.
Also if you look at the two bits of the map together that someone on serebii spotted:
You can see it's not quite so linier and it kind of reminds me of kanto how all the cities seem to circle round with a bit jutting off, this also makes me believe there's definately going to be something in the way at parts etc and you need to go round, on top of this the map doesn't go into the middle which makes me think the map isn't complete and possibly you could walk through the middle where that special internet wifi thing place is.
All in all I believe this is definite a town map of some sorts, not a train map.