Before director James Gunn and film producer Peter Safran were made CEOs of DC Studios, the initial plans for the DCEU were to adapt the iconic comic book event Crisis on Infinite Earths.
The "Nick Fury" of the DCEU
In June 2020, The Hollywood Reporter revealed, to the shock of fans, that Micheal Keaton was in talks to return as Batman in The Flash. More importantly, according to the outlet, if the deal went through, Keaton "wouldn't just return for Flash" but also reprise his role "for several other DC-oriented film projects."
Sources even told THR that Keaton was being envisioned in a Nick Fury-like role, who would be "something of a mentor or guide or even string-puller" to other characters. The outlet had even correctly predicted that Batgirl would have been one of those film projects.
The Tax Write-Off of Batgirl
The film had a reported budget of $70 million and starred Leslie Grace as Barbara Gordon, Michael Keaton as Bruce Wayne, J.K. Simmons as Commissioner Gordon, and Oscar-winning actor Brendan Fraser as Garfield Lynns, aka Firefly.
Keaton's role in the film would have been an "age-appropriate" Batman that was "retired," with him essentially being a "pivotal cameo" throughout the film "when he pops in and out." No doubt acting as a mentor to Grace's Batgirl.
However, according to Safran, one other reason given for the film's cancellation was that it wasn't "releasable" and "would have hurt DC" and "those people involved." Of course, after three back-to-back box office flops, it's hard to believe that Batgirl would have hurt DC's reputation any more than Black Adam, Shazam! Fury of the Gods, and The Flash already have.
Nixed Cameo in Aquaman Sequel
Keaton had already filmed a cameo for Aquaman and the Lost Kingdom, as he would have been the new Batman moving forward after The Flash. However, Warner Bros. had restructured its release schedule in March 2022, and his cameo would have caused a continuity error between The Flash and Aquaman 2.
The Flash had been moved from November 4 to June 23, 2023, and the Aquaman sequel from December 16 to March 17, 2023.
Keaton's cameo was replaced with Ben Affleck reprising his role as Batman. It could have also been an excuse for Warner Bros. to belay replacing Affleck in the role, which didn't end up mattering anyway since Affleck's cameo has also been scrapped.
Burying Batman Beyond
Sometime before December 2022, Warner Bros. had scrapped a live-action adaptation of Batman Beyond, which would have starred Keaton as a past-his-prime Bruce Wayne handing down the mantle of Batman to someone else.
The film would have been written by Christina Hodson, previously credited for writing DC's Birds of Prey and The Flash.
Weirdly enough, in March 2023, it was reported that an animated movie based on the 90s cartoon was also being developed at Warner Bros. to rival Sony's Spider-Verse. No matter its nebulous state, scrapped or not, it's unlikely it would involve Keaton.
The Flash's Original Ending
Warning: The remainder of this article contains spoilers for The Flash
The Hollywood Reporter recently reaffirmed that the original ending for The Flash would have been on the courthouse steps with the appearance of Sasha Calle's Supergirl and Michael Keaton's Batman, reversing their deaths and signaling to Barry that he hadn't fixed the timeline.
This ending was reportedly screen-tested "several times." Regardless, it was scrapped when plans began to change upon Discovery's acquisition of Warner Bros. When Toby Emmerich and Walter Hamada were ousted and replaced by Michael De Luca and Pamela Abdy, who were temporarily tasked with overseeing the DC films.
But, once Gunn and Safran were put in charge, the ending was radically changed, removing everyone, including Keaton. Instead, Calle, Keaton, Cavill, and Gadot were all replaced with Geroge Clooney reprising his role as Bruce Wayne while keeping the idea of Barry not fixing the timeline.
The Flash is currently playing in theaters.