Lois Lane's original DCEU arc made the character much more important to the overall story, but Zack Snyder's departure left it unfulfilled. One of the most discussed aspects coming out of Batman V Superman: Dawn of Justice in 2016 was the Knightmare sequence, which saw Batman receive a time-traveling warning from The Flash about an apocalypse to come, and a vision of what that future held. In the Knightmare world, Superman had been corrupted into a villain, and Flash let Bruce Wayne know that Lois Lane was the key to preventing that result.
Of course, fans have had to wait over five years to actually learn where that story was originally meant to go, as Joss Whedon's widely panned theatrical cut of Justice League completely glossed over that arc. It was one of many casualties of the switch between original director Snyder and Warner Bros.' chosen replacement, the now embattled Whedon. It's but one of the reasons that fans were so desperate to finally see the Snyder Cut of Justice League, an opportunity HBO Max will afford them on March 18.
Sadly, Snyder has made it known that his Justice League will end on a cliffhanger, in line with his original intention to make a Justice League 2 and 3 that would wrap-up the story. In the meantime though, here's how Snyder's original DCEU plan would've made Lois Lane into the franchise's most important character.
Zack Snyder Originally Planned a Lois and Bruce Romance
It's unclear if any elements of this planned sub-plot survived to be part of Zack Snyder's Justice League, as Snyder went through three different versions of the script before production, but his original plan was to have Bruce and Lois get romantic. Or at the very least become closer, with Batman falling deeply in love with the intrepid reporter. That led to a dramatic conflict for the Caped Crusader, as Bruce comes to realize that he'll need to bring back Superman to save the world, but that if he does so, Lois will be lost to him. Whatever she might feel toward Bruce, Clark Kent will always be Lois' true love, and if he's alive again, he'll be who she wants to be with.
According to Snyder, Warner Bros. wasn't keen on this love triangle idea, so while it's not 100 percent clear when during the writing process it was removed, there's a good chance the Bruce/Lois romance won't be part of what's ultimately seen on HBO Max. While this might seem like odd territory for Snyder to want to delve into in Justice League, DC fans might recall that a relationship between Bruce and Lois isn't an unprecedented event, either on the comic page or the animated DC universe. One place such a pairing hasn't been seen before is a live-action movie, so Snyder was likely interested in doing something new with the characters. Whether it would've been well-received by fans is another matter entirely.
Lois' Death is What Caused the Knightmare Future
In accordance with The Flash's warning to Bruce Wayne in Batman V Superman, Lois Lane was indeed the key to why the Knightmare future with an evil Superman happened. However, it wasn't anything she did, but rather something done to her. As revealed by Zack Snyder in 2019, Lois was slated to be killed by Darkseid, which would cause Superman to succumb to the Anti-Life Equation and become a villain. The rub was that Lois would've been killed inside the Batcave, and Superman would then blame Batman for her death, explaining why Batman is public enemy number one in the Superman-dominated Knightmare future.
With the additional context provided by Snyder's later reveal that Bruce had fallen in love with Lois, another whole layer has been added to the Superman/Batman beef in the Knightmare timeline. It also explains why Superman said "She was my world and you took her from me" to Batman. Superman could believe that to be true in two senses, her death, and Batman's romance with Lois, which again, Snyder hasn't really elaborated on as to how two-sided it really was. If Lois did have romantic feelings toward Bruce, even if she did still love Clark more, that's another reason for Superman to hate Batman's guts. As a handsome billionaire, Bruce Wayne probably has lots of romantic options, yet he chose the woman Clark loves. There's no way that doesn't cause a rift even if she hadn't been killed by Darkseid.
Lois Lane Wasn't Just the Key to Superman, But Snyder's Whole Superman Arc
Even aside from her death causing Superman to turn evil, Lois Lane was already setup as an extremely important character to Snyder's original Superman and DCEU story arcs. In Man of Steel, she's able to figure out that Clark Kent is Superman before anyone else. In Batman V Superman, she's able to figure out Lex Luthor's plan to pit Batman and Superman against each other, and is instrumental in them eventually ceasing their conflict and joining forces. She even directly prevents Batman from striking a possibly fatal blow on Superman by explaining what's really going on, albeit after the film's infamous "Martha" moment occurs. While Lois' demise caused the Knightmare future, even in death she was meant to lead Batman to his final redemption.
Batman, wracked with guilt about Lois, but also full of love for her, would've ended Snyder's original Justice League trilogy by traveling through time and sacrificing himself to save Lois and stop Darkseid, preventing the Knightmare timeline from coming to pass. In hindsight, this would've only furthered the often noticed parallels between the DCEU's Batman and the MCU's Iron Man. Either way, Lois would once again prove the deciding factor in a major DCEU event taking place. Again though, it's worth noting that much of this plan was scrapped during further script revisions by Snyder and writer Chris Terrio, due to Warner Bros.' being cool to the Batman/Superman/Lois romantic triangle. Whether or not it would've worked for fans is something we'll never get to know for sure.