Suicide Squad is planned for 2016 (lol) and they didn't think this out? They should all be communicating, and this appearance in a film releasing (lol) the same year as Dawn of Justice should have been locked in or abandoned when the original negotiations were completed.
Some planning and foresight would go a long way towards building a cinematic universe.
This is like Marvel has no planning when
1)Negotiating with RDJ to appear in Captain America 3, which is out 3 months before Suicide Squad!
2)Haven't cast Doctor Strange which is also out that year.
They found a director they liked, perhaps he had a different vision, and trying to work with Eisenberg, who apparently is in demand with several other films (Now You See Me 2 and a possible Zombieland sequel)