WB has also updated the Batman Vs. Superman synopsis last month with the release of the Blu-Ray which includes mention of the Justice League characters:
Directed by Zack Snyder and distributed by Warner Bros. Pictures, the film is a follow up to 2013's Man of Steel and is the second installment in the DC Extended Universe. It was written by Chris Terrio and David S. Goyer, and features an ensemble cast that includes Ben Affleck, Henry Cavill, Amy Adams, Jesse Eisenberg, Diane Lane, Laurence Fishburne, Jeremy Irons, Holly Hunter and Gal Gadot. Batman v Superman: Dawn of Justice is the first live-action film to feature Batman and Superman together, as well as the first live-action cinematic portrayal of Wonder Woman, Aquaman, Cyborg and The Flash. In the film, criminal mastermind Lex Luthor manipulates Batman into a preemptive battle with Superman, whom Luthor is obsessed with defeating.
The general public is concerned over having Superman on their planet and letting the "Dark Knight" - Batman - pursue the streets of Gotham. While this is happening, a power-phobic Batman tries to attack Superman. Meanwhile Superman tries to settle on a decision, and Lex Luthor, the criminal mastermind and millionaire, tries to use his own advantages to fight the "Man of Steel".