According to WeGotThisCovered sources, Christian Bale doesn’t mind returning to the role of Batman and making a cameo appearance in The Flash. The studio is said to have contacted an actor who is ready to play the character again, but only if the idea gets the approval of Christopher Nolan, the director of the Dark Knight trilogy.
At the moment, this information is just a rumor, not confirmed by any major publication or representatives of the actor.
Earlier it was reported that Warner plans to turn to Bale in case of unsuccessful negotiations with Michael Keaton, who may also return to the screens as Batman. It was noted that the studio does not intend to address a similar proposal to Ben Affleck, who played the Dark Knight in Batman v Superman and Justice League, but later the director confirmed that the actor would try on the Batman image again.
It is assumed that with the help of the characters Keaton and Affleck, Warner studio will introduce the viewer to the multiverse – a set of alternative realities that explained different versions of the characters in the comics. In the case of the MCU, this will allow the studio to combine characters from different films on screen, if necessary.