Will Flash or Green Arrow or both ever be on D.C. Universe? Also, will we ever see a Batman Series? If not, why not? We’ve been waiting since the 60’s for another one and not one that’s goofy. 
Batman is too big to have a live action tv series on cable. On this streaming service it may be different but that remains to be seen. He brings in a solid amount of their revenue so naturally he would have a movie. Animated series would be different is something different. But they have already done that so it would have to be something completely new.