"After a year of having the incredible honor of developing with the wonderful and talented people at Lucasfilm, I'm making a personal decision to move forward on a different path. I've put a tremendous amount of thought into this, and I know deep down in my heart that I want to pursue some original creative opportunities. That said, the Star Wars universe has always been one of my biggest influences, and I couldn't be more excited to witness its future alongside my millions of fellow Star Wars fans."In other words it reads as "creative differences." Which while common for Hollywood, is not common for a director trying to build his career and credentials. Nor is it common to turn down one of the largest franchises in history that would not only have netted him a ton of money over the course of his life and benefited his director career to the point he probably get to choose whatever project he wanted. Basically for him to "voluntarily" give up this job would be like you getting the winning multi-million dollar lottery ticket and choosing to tear it up instead of cashing it. That just isn't how human nature works.
Before I could post this, The Hollywood Reporter confirmed my doubts by reporting he was flat out fired by Kathleen Kennedy based on problems from the set of the Fantastic Four as reported to her by Star Wars and Fantastic Four producer Simon Kinberg. It seems that the director was often unavailable (which would grind much of production to a halt) and indecisive (a no-no for any director considering the volume of work that needs their approval). To be blunt it comes across like the director was high as a kite most of the time. This resulted in producers having to step into director-type roles, expensive re-shoots including filming in late April and replacing the film's editor. Considering that Star Wars is one of Disney's crown jewels, they wouldn't want to risk damaging the franchise on a director that doesn't seem up to a task will be several orders of magnitude more difficult with a level of required decision making and pressure that would make doing the Fantastic Four seem like a walk in the park. Even if the stories are not true, its still too much of a risk for Disney to make and so Trank is no longer in a position to make a career defining film. Trank better hope Fantastic Four doesn't bomb because there is no way his directing career could recover from that one-two punch.