There already seems to be a main light source that moves, it happens when loading in and looks like fast forwarding a couple hours. Not sure what this is about.
Not having a day/night cycle is such a pity, the gameplay of nightly raids alone or seeing the landscape at night. Some locations like the goblin camp would look even more stunning if they held their celebrations at night. Astarion could get a slight boost at night etc etc
Dragon Age had frozen in time maps and it was incredibly strange to return to such stagnating maps.