A behind-the-scenes photo from Justice League has confirmed the 2017's movie post-credits scene was added after Zack Snyder left and Joss Whedon took over.
A screenshot of cinematographer Simon Firsht's showreel shows Lex Luthor actor Jesse Eisenberg standing in front of a clapboard. A closer look at the film slate shows Whedon's name, indicating the Avengers director was responsible for filming the post-credits scene that ran at the end of the theatrical cut. This suggests the scene won't appear in Zack Snyder's Justice League as the director has claimed he will rely on what was shot before Whedon took over.
Whedon's Justice League set up a potential arc with the Legion of Doom when Luthor recruited Deathstroke's services. Apart from that, neither Eisenberg nor Joe Manganiello appeared in the rest of the movie. Justice League was supposed to be the start of Manganiello's tenure of the famed assassin and lead to a standalone Deathstroke movie from The Raid's Gareth Evans. Manganiello was one of the many stars to throw his support behind the #ReleasetheSnyderCut campaign but has remained tight-lipped on plans for Deathstroke.
Snyder has been drip-feeding fans snippets of what was supposed to be in his movie, including more focus on Ray Fisher's Cyborg and the reveal that Man of Steel's General Swanwick is Martian Manhunter in disguise. While Zack Snyder's Justice League could also put the original post-credits scene back into the movie, his cut of the movie will reportedly be the end of his DC Extended Universe.
Justice League stars Ben Affleck as Batman, Gal Gadot as Wonder Woman, Henry Cavill as Superman, Amy Adams as Lois Lane, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, Jeremy Irons as Alfred Pennyworth, Diane Lane as Martha Kent, Ciarán Hinds as Steppenwolf, Jesse Eisenberg as Lex Luthor and J.K. Simmons as Commissioner Gordon. Zack Snyder's Justice League will premiere exclusively on HBO Max in 2021.