"Em desenvolvimento" não significa muito WRT em um filme, então era perfeitamente normal que a Warners estivesse envolvida em vários projetos ao mesmo tempo. Especialmente quando há vários "chefes" envolvidos :
And then, all of a sudden, Warner Bros. seemed to change its mind about Batman vs. Superman. Studio President Alan Horn was apparently convinced it was better to relaunch both heroes separately, with J.J. Abrams’ Superman script and some version of Aronofsky’s Batman origin story. Horn distributed copies of the Batman vs. Superman script and Abrams’ Superman: Flyby script to 10 Warner Bros. execs, and they all preferred the Superman script.
Warner Bros. VP Lorenzo di Bonaventura was still a staunch supporter of Batman vs. Superman, and argued that they could do the team-up movie first and then release Superman: Flyby. But J.J. Abrams, in one meeting, reportedly told di Bonaventura that “You can’t do that,” because it would be akin to releasing When Harry Divorced Sally followed by When Harry Met Sally.
In the end, according to Hughes’ book, the fate of Batman vs. Superman apparently came down to Alan Horn versus Lorenzo di Bonaventura — and after BvS was killed, di Bonaventura left the studio a few days later.