All of Tamriel is (maybe) in Skyrim

So there's this Finnish blogger by the name of Jesse who broke through the invisible wall connecting Skyrim to Morrowind. Guess what he found. The whole province of Morrowind. And then from Morrowind he traveled to Cyrodiil. Yes, it seems very probable that the entire land of Tamriel has been programmed into the game. But why? That certainly is the question. Popular speculation is either for DLC or modders, since many modders often recreate other provinces in TES anyway. These areas are't completely accurate or to scale, at least in relation to their respective games. There could be several reasons for this. They could be in there to provide some context of the for the 3D map, but that seems unlikely to me. There's just too much land created here, even if it isn't entirely accurate. My theory is that, taking place 200 years after Oblivion, the landscape could have changed somewhat. For example:

Oblivion above. Skyrim below.

I imagine that if that lake started to dry up, you might get something like the Skyrim version. No, there's definitely a reason for the existence of these landmasses that related to the gameplay. I mean, the path that leads to Morrowind is blocked by a wall, but that wall has an open walkway. Bethesda stated before that there would be less DLC for Skyrim, but that it would be more substantial. Perhaps a trip to Morrowind or the Imperial City is in order?