Could Justice League part 1 center around Captain Marvel and Black Adam??
I get the feeling they might be leading upto an injustice league with Luthor in BvS, Black Adam in the Shazam movie, and the villains that'll come out of their future projects. But I think that might be in the next half of the JL movies, their phase 2. Phase 1 seems like it might be Braniac or Darkseid.