While Zack Snyder has been given the opportunity to film additional material for the cut of Justice League coming to HBO Max, it doesn't appear as if the filmmaker will be able to tie up every loose end. After all, he did once have plans for a Justice League: Part 2 before Warner Bros. pulled the plug.
It's possible that he will get to tell that story, but highly unlikely, especially when bringing that cast together again would be a major challenge for any studio. There has, however, been talk of a comic book continuation, and Snyder has talked to Jim Lee about delivering a sequel in that format.
During a recent interview (via Bleeding Cool), the director revealed what that would look like, and even shared some plot points he hoped to address in a Justice League sequel.
"I would love to do a comic book, the post-apocalyptic Knightmare world, the world has fallen, the ragtag team that's left alive trying to put it back," Snyder explains. "Inside of that story, we would also do that story of Joker Killing Robin. The Joker is somehow involved in the stealing of the Mother Box and using it to create the treadmill; Cyborg is going to do the math, this is what we're going to have to do to jump back in time and warn Bruce correctly."
"A lot of the conflict would be Bruce reliving the death of Robin and what went into that."
Snyder would go on to say, "I don't think anything is going to happen right away, but Jim and I talked about it quite a bit. And talked a lot about maybe doing a book, or a comic book down the road to kind of finish this. We haven't locked anything yet. Even just the death of Robin in that world would make a nice little one-off."
It's thought that the "Snyder Cut" of Justice League will explore that Knightmare setting to some degree, with Jared Leto expected to play the Clown Prince of Crime from that timeline. For now, it seems we can only hope that Snyder will team up with Lee for a comic book sequel, but it's clearly still early days.