If I was running things at WB for the DC movies I would first do a "Son of the Bat" movie with Batfleck that introduces Damien Wayne and ends with him taking up the Robin mantle and then move into a Titans movie featuring the characters from the Teen Titans GO cartoon (Robin, Cyborg, Beast Boy, Starfire and Raven) since those are the most familiar to audiences so you can get the kids that love TT Go to want to see the movie.
Then I would just make a movie that was less dark than what DC films usually are but not over-the-top like TT Go...basically a straightforward action flick with some humorous elements.