It has been revealed that Super Buu with Son Gohan absorbed and Dabura will be joining Dragon Ball Xenoverse 2 as playable characters in the upcoming paid DLC of Dragon Ball Xenoverse 2. Additionally, Zamasu will be available as a master, in which you will be able to learn various attacks from him.
Dragon Ball Xenoverse 2 is now available for PlayStation 4, Xbox One and PC, and will be available for Nintendo Switch next week
The scan below mentions Nintendo Switch and PS4 specifically since those are the platforms the game is on in Japan, but we surely expect this expansion to made its way to Xbox One and PC/Steam as well! This expansion pack DLC is expected to be released on an unannounced date later this year.