I still think it's just a designer being bored and adding it in, rather then any idication of DLC.
Well, Oblivion also had the terrain for the surrounding provinces and we never got DLC to go to them.
People have been clinging to straws about Province DLC and they really do need to think about the logistics. Morrowind and Cyrodil are just the low detail distant land textures and meshes.
To add the higher detail 'close up' textures and meshes, to place buildings, settlements, citys, caves, ruins, trees, items, NPCs, to write dialogue and scripts, to do all the voices, all the quests and the nav meshing AND THEN bug test the whole thing, it'll take as long for each province as it took for the entire game.
Too many people have taken the 'evidence' of the provinces and Beths statement that DLC will be larger and basically added 2 and 2 and made 53.