Isn't There supposed to be an impassable terrain here?

Red circle marks where the impassable terrain would be in the border between Ma Clique and Fengtian Government

After the No Compormise, No surrender Dlc released, I found that there were some inconistancies in the map. I am playing a game as the Federalists, and when I made the Chinese United front, I found that the impassable terrain here is missing. Is that supposed to happen?