I just heard there was gonna be a Batman Beyond movie if The Flash was successful but it got cancelled due to The Flash being a box office flop. In a world where The Flash was actually a box office success, we could have gotten this. Batman Beyond is a prequel to The Flash that leads up to his retirement. It will follow the storyline in the comics but Bruce Wayne will not die in the movie because... I don't wanna spoil The Flash but if you've seen the movie you know what I mean.