The next Pokémon movie (that doesn't star a sleuth version of Pikachu) is a CGI remake of the first one, except that it will include at least one significant change, as a new trailer has revealed that a new armored form of Mewtwo will be appearing in the film.
There have been rumors circulating that the upcoming Pokémon Sword & Shield for the Nintendo Switch will feature a new kind of evolution known as Armored Evolution and that at least four Pokémon will be able to use it - Charizard, Flygon, Mewtwo, and Zeraora.
A new trailer has been released for Mewtwo Strikes Back Evolution which shows Mewtwo wearing a brand new suit of armor that wasn't in the original film. In the Pokémon anime, Mewtwo debuted while wearing a suit of robotic armor that had been given to it by Giovanni, which it later removed when escaping from Team Rocket's control.
The new suit of armor that Mewtwo is sporting in the Mewtwo Strikes Back Evolution trailer is far more intricate than the one worn in the original anime, which suggests that it may be tied to the rumors of the new armored form of Mewtwo that is said to appear in Pokémon Sword & Shield.
Mewtwo doesn't wear armor for very long in the original version of the first Pokémon movie, yet the fact that it was shown so prominently in the trailer suggests that there is more to Mewtwo's new outfit than meets the eye. It's possible that the new suit of armor worn by Mewtwo in Mewtwo Strikes Back Evolution will be retconned into being whatever the Armored Evolution form of Mewtwo will be in Pokémon Sword & Shield.
Mewtwo Strikes Back Evolution isn't the only CGI Pokémon that is due to be released this year, as Pokémon: Detective Pikachu will be out soon and Mewtwo is confirmed to appear in that film as well. It's possible that Detective Pikachu may also give us a glimpse at Mewtwo's new form from Pokémon Sword & Shield.
Mewtwo Strikes Back Evolution is due to be released in Japan on July 12, 2019.