"a more open path" is probably meant figuratively in this case. Imagine a path through the woods. This path can be overgrown by weeds and scrubs, partially blocked by branches that haven fallen from the trees, treacherous to walk, slowing you down. Or the path can be cleared from all obstacles, which allows you to walk faster and more easily to your destination. A path that's free from obstacles is called an open path.
According to Chris Aronson, the movie had it easier on the figurative "path to success" at the new release date, because the path was more open, with less obstacles at that new date than it would have been at the original release date.