Setting the Flashpoint
Ezra Miller’s Flash is a scene-stealer who brings quite a few Easter eggs along with him. The gorilla sign-language could be a Grodd tease. Based on the schematics in his headquarters, we assume he’s already battled Captain Cold, he’s a Batman fan, and his origin is oversimplified.
Most importantly, the movie teases the Flashpoint. When Flash meets his father (who’s also in the movie, despite rumors saying otherwise), he’s urged to make his own future, which is a bit on-the-nose for DC Comics fans.
He knows that his father didn’t kill his mother. The movie’s conclusion makes it clear that Barry becomes a police scientist, which should give him an edge when he investigates her murder.
In Superman, Flash has someone who will push him to become better and faster. Prior to joining the League, he ran on his own, but now he has Superman to race against. One of the best scenes of the film is the one in which he realizes that someone else is as fast as he is. This means that his abilities and powers will be honed by time we see him again.
Read More: Is The Flash Faster Than Superman?
The point is that so far Flash hadn’t been aware of his ability to time-travel. But he’ll discover it as soon as Superman’s speed pushes him over the limit!
To be noted, Iris West was also supposed to appear in the film. Her unfinished scene was leaked online almost immediately as Justice League was released.
