Much has been made of the value of Microsoft and Sony's various upgrade deals, which allow players to buy the next-gen version of a current-gen game they own at minimal cost. But buyer beware: you won't be able to carry over your single player progress.
Speaking with Kotaku, Activision, EA and Ubisoft representatives have confirmed that single player progress will not carry over to next-gen versions of Call of Duty Ghosts, Battlefield 4 and Assassin's Creed IV: Black Flag. Multiplayer progress on Battlefield 4 and Call of Duty Ghosts will carry over, however, which for many players is the main drawcard in the first place.
Ubisoft has yet to confirm if single player progress in their massive sandbox title Watch Dogs will carry over, but considering the aforementioned restrictions, it seems unlikely.
As noted by Kotaku, these kinds of schemes are unprecedented, so it's not surprising transferring a save file from one platform to a significantly more advanced other isn't exactly a piece of cake. However, it's important information for consumers looking to make an immediate transition from one generation to the next.
Source : ign[dot]com