China Rising is the first in a series of planned expansions for Battlefield 4 and was offered as a free pre-order bonus to anyone willing to put down cash early on any version of the game. At the same time, EA (and many other publishers) were involved in a promotion that would allow players to upgrade a game from its PS3 or Xbox 360 iteration to a next-gen counterpart for a small fraction of the game's purchase price.
Though the official Battlefield Twitter account claims that China Rising should be upgraded alongside the game using the aforementioned promotion, a player using the name "buckethead232" has revealed a text chat with an EA customer service representative which directly contradicts that idea. "According to the latest updates, upgraded players have to purchase [China Rising]," the representative told the player, before adding that the only ways to get China Rising on either a PlayStation 4 or Xbox One are to pre-order a next-generation version of the game, spend $15 to buy the DLC piecemeal, or spend $50 for the Battlefield Premium service (which bundles all Battlefield 4 DLC).
We've contacted EA for further information on this apparent policy change, though have yet to hear back. That's not surprising given that it's two days before Christmas, but we'll offer an update when and if we hear more.