Audiences will have no expectations (besides what they know from Arrow and the comic book source material) and that allows the upcoming Batman solo movie to go off in incredibly new, interesting directions.
When dealing with a character as well worn and well established as Batman, it becomes important for filmmakers to mix things up.
We can only watch Batman fight Joker so many times before it becomes tiresome.
Variety is the spice of life; never let anyone tell you otherwise.