Lately it seems like Zack Snyder is done with whatever restrictions may have been on him in regards to his work with DC Films and Warner Bros., because he's been sharing insights about the DC films he directed (Man of Steel, Batman v Superman, Justice League) with fans, and revealing a lot about what the DC Extended Universe could've been.
A lot of Snyder's revelations have centered on one theme: the buildup to Darkseid's debut in the DCEU, which Snyder had apparently been planning for quite some time, as the big headline event that would've been part of a Justice League sequel. Well, now we have Snyder confirming yet another piece to the puzzle he was building: how Lex Luthor's final monologue in to Batman at the end of Dawn of Justice, was a direct foreshadow of Justice League's major plot MacGuffins:
As you can see above, Snyder snuck in a nice, sneaky, little tease of the DCEU Motherboxes that were Justice League's main focus - in a way that very few DCEU fans seem to have noticed, either before or after Justice League's release. It seems that the manic performance that Jesse Eisenberg gave as Lex Luthor in that finale speech wasn't just over-the-top hamming - but rather a carefully orchestrated speech, meant to set up the full arc of the next DCEU chapters.
Based on what fans already knew, and what Zack Snyder has been revealing as of late, it's now much clearer where Snyder was going with his vision. First, we would've seen Darkseid at a much younger age, appearing in the flashback to Earth's ancient war with Apokolips. Darkseid would come to Earth searching for a weapon that Snyder teases would've made him unbeatable - and would've returned again, to finish the war he retreated from in those ancient times.
Fan speculation has now turned toward what, exactly, Darkseid was looking for. The concept art of Young Darkseid seems to indicate his war on ancient earth took place before Darkseid had his iconic "Omega Effect" powers, which could've have been what he came to Earth for in the first place. The other big guess is that Darkseid figured out the dreaded "Anti-Life Equation" was hidden on Earth, and would invade both in the ancient past and present day, in order to pull a Thanos-style cleansing of the universe.
While a lot of that sounds awfully close to Marvel's Avengers: Infinity War and Avengers 4 plotlines, it still would've been an epic arc for one of DC Comics' biggest and best villains, and would've seemingly pulled together so many of the threads and clues that Snyder had been peppering into Man of Steel, Batman v Superman, Justice League and even Wonder Woman. In short: there was a vision for a united and fully interconnected DCEU - but now it only exists in the Snyder Cuts.
Upcoming DC Extended Universe films include Aquaman on December 21st, Shazam on April 5, 2019, and Wonder Woman 2 on November 1, 2019.