The future of Pokémon films isn't quite clear, but the appearance of Mewtwo in Pokémon Detective Pikachu has some major implications for the future of the universe. Fortunately, it looks like those avenues will have the opportunity to be explored now that there's finally a great video game film. Detective Pikachu performed better than Avengers: Endgame on its opening Friday, too, and it's likely that this success will continue throughout its run.
Based on the strong reviews for Detective Pikachu, it's clear that the cinematic take has worked. And, after seeing the events of the film play out on the big screen, the focus then shifts to the future of the franchise. The writers behind Detective Pikachu have talked about how they'd set up a live-action Super Smash Bros. movie, but it's the events of Pokémon Red and Blue Versions for the original Game Boy that may be set for an on-screen adaptation next.
During one particular scene in Detective Pikachu, the head scientist that's running experiments on Mewtwo makes a throwaway comment that has massive implications. Prior to capturing the Legendary Pokemon for use in her tests, she states that Mewtwo was last seen as it escaped the Kanto region 20 years ago. Keen players of the original games may recall that these events led directly into Pokémon Red and Blue, where Mewtwo freed itself after being created by Team Rocket scientists and taken refuge in the Cerulean Cave.
Now, the 20-year gap could mean any number of things when it comes down to fitting Detective Pikachu into the timeline of Pokémon. Truthfully, there are so many events that play out in different ways across the games, manga, and anime. It would only make sense that the same sort of approach will be applied towards future live-action Pokémon films as well, but acknowledging the events that led to Mewtwo's creation is a fun nod to Red and Blue.
There are plenty of nods to other regions throughout the film, but none are as significant as the reference to Mewtwo. Of course, this means that the original protagonist Red is likely to be running around the world of Detective Pikachu as well. That's a story that would be wonderful to see told, but for now, it remains a reference that could serve as a jumping on point for the future direction of the Pokémon film franchise.