David F. Sandberg has confirmed that he’s directing Shazam! as part of Warner Bros.’
However, the latter two movies would focus on characters that weren’t confirmed to appear in Snyder’s upcoming Justice League film.
Last year, all of the confirmed DCEU directors showed up on stage during the studio’s panel at SDCC.
There’s also the fact that Snyder has temporarily departed Justice League following a personal tragedy, thereby leaving Joss Whedon in charge of the movie’s reshoots.