Zack Snyder's Justice League evolved considerably over the course of its development and production processes. It's clear that there was a bigger story that Snyder wanted to tell before departing the project, and much of that related back to the origin of the Mother Boxes. In fact, the director has taken to social media to share some early storyboard work from Justice League, and it looks like he had plans to explore the box's history with the Nazis during World War II. Check out the picture, below.
As you can see, there was a much broader idea at play in Zack Snyder's early visions for the Mother Boxes in Justice League. In fact, the director even planned to show how the Nazis got their hands on the Mother Box at the end of WWII. Going into great detail about the artifact's history in the DCEU timeline, Victor would explain how it eventually found its way into American hands and went on to become the device that turned him into the Frankenstein-esque member of the Justice League.
Eventually, the storyline teased in Zack Snyder's Vero post shifted so that Steve Trevor's team found it after the events of Wonder Woman (i.e. following World War I's conclusion), and the cube's path to S.T.A.R. Labs was left considerably vaguer. From there, the cube was used to create Cyborg, and the three boxes eventually went on to become the primary McGuffins of the first theatrical Justice League movie. In the words of The Flash, "No fuss, no muss."
Of course, there's an argument to be made that this was probably for the best in the long run. Nazi scientists getting their hands on a powerful cube sounds like a pretty badass storyline for a superhero movie, but it's also virtually the same plot thread that carries Captain America: The First Avenger through to The Avengers on the other side of the aisle in the Marvel Cinematic Universe.
While this storyline ultimately found itself omitted from Justice League, it's worth wondering if the DCEU may eventually return to WWII to explore similar avenues. We know that Steven Spielberg will produce and possibly direct a Blackhawk movie, and while there's no confirmation that this project will exist in the DC Extended Universe, it could go a long way towards fleshing out the existing mythology if it is. There's plenty of room to work with here, so Zack Snyder arguably may have been onto something.
Only time will tell what the future truly holds for the Mother Boxes, the Justice League and the DCEU as a whole. With that in mind, we will bring you more updates related to this ever-expanding cinematic universe as more information is made available to us. As for the rest of this year, make sure to watch out for James Wan's Aquaman when it finally debuts on December 21.