Similarly, there appears to be a mountain path slightly noth of Route 27 which doesn't connect to anything significant on either end... Unless, of course, it's a piece of track that's been exposed to verify the Magnet Train's return.
EDIT: I've found a larger version of the map. Since the six squares of land northwest of Cianwood appear to be divided by "elements", it might be the game's Pal Park. Additionally, note the reoccurence of the Battle Tower in its original Crystal location, just west of Olivine. It's mostly obscured by clouds, but its base is clearly visible.