Zack Snyder's Justice League is proof that a Man of Steel sequel is something that Superman fans still need. The film not only introduced the world to actor Henry Cavill as Superman for the modern age but was the foundation of the entire Warner Bros and DC Films franchise that followed. Now that the Snyder Cut is out, it certainly leaves the door open for what's next in the story of Cavill's Superman, as well as setting the stage for finally re-introducing the more colorful and hopeful version of Superman that so many movie fans have been asking for.
The solo Superman franchise has been stalled (if not dead) since Zack Snyder rebooted it with Man of Steel back in 2013. The film was divisive in its portrayal of Superman for the modern age - the first split in the DC fandom that would only widen as Snyder released Batman v Superman: Dawn of Justice in 2016. Of course, Snyder was always fairly transparent that Man of Steel and Batman v Superman were both extended origin stories for how and why Henry Cavill's Superman goes from being a flawed and would-be hero to the symbol of hope and justice that many fans see him as. That was a transformation that was supposed to be completed in Justice League - but that vision was never realized. Instead, we now have Zack Snyder's Justice League, a project which has undoubtedly evolved since it was originally supposed to be released in theaters.
The Snyder Cut of Justice League does a much better job of both showing how Superman returns from the dead and recovers his sense of self - while also providing all the reason for him to be looking toward becoming a brighter and more positive symbol in the world: he's going to be a dad. On the other side of that same coin, Zack Snyder's Justice League also took one more step closer to that very dark and ominous version of the future in which Ka-El falls under the sway of Darkseid and the Anti-Life Equation.
The prospects of Justice League 2 happening (or at least happening within the "Snyderverse" framework) or pretty slim to none at this point. However, DC/WB have already successfully spun their new brand of DC movies out of the DNA of the Snyderverse (see: Wonder Woman and Aquaman); The Flash movie will be a big continuity reset for the DC Films franchise, but Man of Steel 2 may be the best spiritual "bridge" between the old and new DC Films franchise.
After Snyder's Justice League, Superman running around in a black suit seems like it would have to come to an end before he becomes a new dad. Indeed, the themes of how Clark/Kal-El faces the prospect of parenting, given all he's done and been through, would be a powerful story to tell. One that could force even Superman to struggle with what ideals to hold dear, and what it takes to make a better world and future for future generations. It's a story that would appeal to the entire generation of adults that grew up on Superman movies and are now parents - and also a meta-reference to the serious struggles the Superman character and franchise have had in trying to carve out space in the modern world.
More importantly, Man of Steel 2 is the opportunity to give Henry Cavill a chance to play the brighter and more hopeful Superman fans have waited to see him get the opportunity to play. It's a safer bet than whatever comes with the new Superman movie project (with a black character) that Warner Bros. is working on - and some much-needed potential closure for fans the first film.
Zack Snyder's Justice League and Man of Steel are both streaming on HBO Max.