V-Jump magazine has revealed that the upcoming Dragon Ball: Xenoverse DLC Pack 3 for Japan (and most likely for the west as well) will not only have Golden Frieza as a playable character, but SSGSS (Super Saiyan God Super Saiyan) Goku and Vegeta as well.

An extra mentor has also been added Old Kai (Elder Kai) will be a mentor along with Jaco. If I had to guess, Elder Kai will probably be unlocking your potential. Towards the bottom SSGSS Goku will be a playable character in the Japan only arcade game Dragon Ball: Zenkai Battle Royale.