Back in November of last year, a report surfaced that claimed Joss Whedon was no longer directing the Batgirl movie, but it was not confirmed by Warner Bros., DC Films, or the director.
In the end, it seems that Joss Whedon and Warner Bros. and DC Films had an amicable split.
In a new statement, Joss Whedon announced that he is no longer directing the Batgirl movie after months of speculation that he had left the project.
So, it might not have been all on Joss Whedon to leave the project.