The DCEU has a Cyborg solo movie is unlikely). Superman's future ends abruptly with The Justice League's Snyder Cut event. Beyond that, there's no indication that any more Superman solo movies will happen or even if Henry Cavill will remain in the part.
Superman was actually the founding stone of the DCEU, having kicked off the entire shared universe even before it was a fully-formed idea with Zack Snyder's Man Of Steel, but Justice League did serious damage to the character. Already often considered to be too difficult a character to adapt to the big screen in modern - and more cynical - times, the Blue Boy Scout is accused of lacking the necessary conflict to make great movies. Fundamentally, he's just too powerful. That argument isn't entirely true, but it also isn't entirely baseless either.
The most left-field approach Warner Bros. could take with Superman to address the complaints around conflict would be to take not just a leaf out of Marvel Comics' book, but an entire comic book character. In short, the DCEUe should borrow Marvel's Sentry story.
Sentry Was Marvel's Answer To Superman
Introduced in the 2000 Marvel Knights miniseries written by Paul Jenkins with art by Jae Lee, Sentry quickly established himself as one of the Marvel Universe's most powerful characters. Deriving his powers from a supercharged version of the same super-serum that gave Captain America his powers, Sentry is essentially omnipotent and immortal, with a power-set that remains unclear because of the restraint he showed in using them. In other words, he was Superman with a booster injection, but his story offered a means to write conflict into his life to make him more than just a shiny golden god.
Sentry's deal was that he had an equal and opposite force called The Void who he projected as a dark reflection of his powers. Every time he did something for good, The Void balanced it with an equal strike for evil - a response, as Norman Osborn so eloquently put it, to the void left in Sentry's life by his superheroism. The story essentially acts as an allegory for creating superheroes with no substance and the correct way to deal with them. In Sentry's story, he co-creates a means to have his own existence forgotten (including in his own mind) to stop The Void from balancing his actions.
DCEU's Superman Problem
Though Sentry was not introduced to Marvel as an answer to Christopher Reeves' version, meanwhile, leaned into the "goodie-two-shoes" side of the character apart from in the excellent Superman vs Superman sequence in Superman III, which tends to be held up as the reason why Superman films are now so hard to make.
Fundamentally, the suggestion that Superman is a difficult subject comes down to either the fact that he will always do the right thing or that he's simply too strong to be threatened. The constant allusions to Superman as a God - or in a thinly-veiled Christ allegory - do the character a disservice by creating a divide. Yes, Superman is hope, but to present him as the God Of Hope is missing the point. But also, the idea of Superman being good because of his upbringing and thus him being an extension of humanity doesn't really make for good cinema. There's less drama there, less conflict and less interest. The answer would be to look again at what Superman stories are actually about - humanity, as Zack Snyder knew - and to steal some of what made Sentry so great to offer something bold and new to the DCEU as part of the new multiverse, perhaps.
How Sentry Can Fix Superman In The DCEU
The Sentry comics' look at Sentry as a superhero imprisoned in the body of a real man who necessarily removed himself for the sake of those he sought to protect is a genius idea. And it's a genius idea for how to handle Superman in the DCEU, more importantly. Because the idea of Superman as a protector is all well and good but as the DCEU teased in Justice League (albeit unsuccessfully), there's a very interesting story to be told on what happens when the Superman is no longer available. In Justice League, that was achieved through his death, but it was all undermined horribly by the post-credits scene on Batman v Superman that heavily teased his return before anyone had a chance to mourn him. Even the idea of an evil Superman - which parallels the story of The Void almost - was great but badly applied.
What Superman film fans have not seen enough of is what the MCU does very well: the question of whether heroes should be heroes. It's been explored in Iron Man movies, Captain America movies, Spider-Man and even Thor movies and it underpins Bruce Banner's existential anxiety prior to his Professor Hulk rebrand. But pushing those Marvel ideas of whether the existence of superheroes actually informs the existence of their enemies - just as The Dark Knight suggested with The Joker - would be the perfect answer for making a new Superman movie franchise. Introducing a villain who is enough of a threat to humanity (and not Superman himself) to force Clark into a crisis on his own existence completely changes the usual dynamic.
If Superman is always presented as untouchable - or at least revivable - there can be no real conflict, but attacking Superman's conscience and presenting the idea that his very existence threatens the world he's pledged to protect solves that issue. There would be no need to continually escalate villains (which the DCEU's villains group did way too quickly) and having Superman first reflect on who he is, what his heroism means, and how he could be endangering the world would make for a compelling story. If the pay-off had to be that the world forgot Superman for its own good and the second stage of the arc mirrored Sentry's required return (when The Void returned to threaten Earth), the DCEU would have its traditional Superman movie, but with the foundation established in a new movie that could be bold and different and challenging.
