Justice League Trailer Breakdown: 28 Things You Must See
11. Cyborg's Flash-Back
This is a strange shot to drop into the middle of the trailer, to be honest, slightly killing the momentum, but fatally.
But then, you can see the implication here: because Cyborg is the least notorious of the characters being introduced here, the film is already establishing that we're going to see his original, unabridged. Nobody else really needs one (since they're all getting their own movies firmly), but mainstream audiences will know very little of him. And Zack Snyder says his story "is in a lot of the ways the heart of the movie."
It would make sense we'll see a version of his classic origin when he is led down a darker path by his friend Ron Evers, who incites racial terrorism, and that his love for athletics over scholastic work will be ported over from the comics too. Whether we'll see a true redo of his transformation into Cyborg - with the interdimensional creature killing his mother and mutilating him remains to be seen.
Maybe the Parademon seen in his father's apartment will do the deed instead?