Bleeding Cool brings us the following:
Originally, Marvel’s Ant-Man was on the calendar for November 2015, but now the studio have decided to bring the picture forward to July 31st.
That’s just two weeks after the Batman meets Superman movie, which arguably shows some real brass on the part of Marvel.
Perhaps more tellingly, it moves Ant-Man out of the way of the next James Bond film. Edgar Wright has made more than a few references to his Ant-Man picture having heavy spying and espionage elements.
The easier move might have been to push Ant-Man back into 2016, out of the maelstrom of 2015. That Marvel didn’t do this highlights the deliberation with which their releases are ordered. As standalone as Ant-Man might be, or might initially appear to be, I doubt it can just be shuffled out of sequence without losing a little of its edge.