RUMOR: “Far Cry 4” Maps Recycled for “Far Cry Primal”
Or maybe "Primal" takes place in prehistoric Kyrat?
According to Game Pressure, they have evidence that Ubisoft recycled "Far Cry 4" maps and put them in "Far Cry Primal."
Game Pressure used maps from both games and pinpointed where the assets were reused, such as the rivers, roads, and the like. Whether the reused assets were intentional so future games could have surprise Easter eggs ("FC4's" Kyrat is NOT in Europe, however, as Central Europe is the area we're told "Primal" takes place) or just to reuse map assets just because isn't known.
Source: Game Pressue