The official
POKKÉN TOURNAMENT Twitter account posted a tweet indicating that there will be an announcement on January 15th, 2016 to reveal a new playable Pokémon.
A hint was given in the tweet indicating that the new Pokémon has the character ラ in its name.
Source:
https://twitter.com/pokken_official/status/685287867120128000
Update: January 15th, 2016
It was revealed that
Chandela was the new Pokémon to be added to the game.