The official release date for DLC Pack 5 is currently being advertised as November 2017.
Bandai Namco Entertainment America has announced the price for Dragon Ball Xenoverse 2: DLC Pack 5 & 6, which are being officially called Extra Pack 1 and Extra Pack 2.
A release date has not yet been announced for this mode, but it will most likely be around the release of DLC Pack 5, if not the same exact date.
The free DLC is in the form of a new mode called Hero Colosseum Mode!