In an interview with the New York Daily News, Zack Snyder revealed the answer to the question that fans have been asking since it was announced that Ezra Miller would be playing the Flash in the DC cinematic extended universe instead of the already established Grant Gustin's Flash. Zack Snyder explains:
"I just don’t think it was a good fit. I’m very strict with this universe and I just don’t see a version where…that [tone is] not our world…Even if Grant Gustin is my favorite guy in the world and he’s very good, we made a commitment to the multi-verse [idea], so it’s just not a thing that’s possible."
This does not mean that fans will not be able to see Grant Gustin in the DCEU or Ezra Miller in one of the Berlanti tv shows. Since they are setting up a multiverse in the DCEU and in Berlanti-land, fans of the CW series may be able to see their favorite flash o the big screen. The multiverse allows for an infinite amount of possibilities, including multiple Flashes or even yet, multiple Barry Allens.
This topic has already been broached in season 2 of "The Flash" in which Barry Allen not only meets another Flash but he also meets another Barry Allen.
Greg Berlanti plans to expand on the multiverse notion in an upcoming crossover event between CW's "The Flash" and CBS' "Supergirl" in an upcoming "Supergirl" episode titled "Worlds Finest". On March 28th, Barry Allen will travel to an alternate universe and land in National City. In exchange for Supergirl's help returning home, The Flash teams up with Supergirl to defeat Livewire and Banshee.
There is plenty of work going into establishing both iterations of the Flash and hopefully, fans will be able to see a crossover event between the movie and TV versions soon.
The Flash movie is scheduled to hit theaters March 16, 2018. In the meantime, fans can continue to enjoy the Flash television series by tuning into The CW on Tuesdays 8/7c.
