However, as pointed out by Collider, this is when Fantastic Beasts 3 is now filming, so what does this mean for The Flash? The most obvious answer is that the superhero blockbuster will be pushed back once again. Even assuming that it starts filming in early 2020, it could still potentially arrive in late 2021.
Article source: https://www.cinemablend.com/news/2465443/how-will-ezra-millers-the-flash-movie-be-affected-by-fantastic-beasts-3-delay