It has been revealed via a trailer on TVTokyo's Youtube Channel that there will be a "Mewtwo's Awakening" special airing the day before the premiere of the 16th Pokemon movie, chronologically taking place immediately before the events of the film. This will mark the first time in thirteen years that a Pokemon special connected to a film has aired, the first coincidentally being "Mewtwo Returns" in 2000. A trailer for the special may be viewed below:
Source(s):[
TVTokyo Official Youtube Channel (Japanese)]