During a conversation with the Hall of Justice podcast (via io9, Zack Snyder discussed the inclusion of other Justice League characters in Batman V Superman: Dawn of Justice: “As far as the other Justice League characters go, they play a very small role. It’s really just a whisper they exist. Except for Wonder Woman, we see her really well. But really the movie is about Batman and Superman. And we really take time with them and we really drill down on the why of them and what they stand for and their beliefs and them as characters. That’s pretty much the why of the movie. But again as I said, it does begin the conversation about these guys are out there.”
He was also asked about DC developing a cinematic multiverse that integrates film and TV: “As opposed to trying to shoehorn all these storylines into a single universe, we let the characters exist in a multi-universe, and it’s a lot more fun, and a lot more value for the audience. [Fans] get to see their favorite, most beloved characters on different adventures at the same time in different universes. It makes it a lot more fun, we get to go in different directions at the same time. I’m like a kid in a candy store with this incredible opportunity. It’s really fun. It couldn’t be any better.“