A good example of what he is trying to achieve is in the game Spore:
Ancel mentions the gameplay, parkour focused, being quite similar to Assassin's Creed. This was demonstrated in the leaked trailer, Jade will be climbing buildings in open environments. As much as a brilliant game AC is, it isn't one without it's problems. I.e. Framerate dips. With BG&E2 potentially being a similar game, this maybe the reason it's become a next gen title as current gen hardware is too limited.
BG&E's art style was good. The game looks gorgeous even today. Games generally with that kind of art style run better in terms of framerate, because of the minimal graphic size. The new realistic look is for showing it as if it were a new IP, they have to make sacrifices to make the game sell better. In fairness, the game still needed to do some growing up, if not visually, the story could be expanded upon on, with some clever twists.