Apparently Warner Bros. Asked For That Ezra Miller CW Cameo Late In The Game

As for whether or not Movie Flash and TV Flash will meet again, that’s hard to say, and Marc Guggenheim added that that question is up Warner Bros and DC. However, he added that the companies, including DC Comics’ Co-Publisher and Chief Creative Officer Jim Lee, have a “wonderful vision” for not just the cinematic Flash, but the entire DC Universe. So perhaps there will be an opportunity for these Flashes of two worlds to have a proper team-up in the years to come.