
The fate of Barry Allen‘s outfit, which was shown in Justice League, is revealed in a forthcoming prequel comic to the upcoming film The Flash.
The Flash is slated to hit theaters next summer, and even though its actor Ezra Miller has continued to garner media attention due to his continuing legal issues, the movie has nonetheless used some of its advertising materials to reveal parts of its plot ahead of time. For instance, “The Fastest Man Alive #1,” a comic book adaptation of the impending film, provides some clues as to Barry Allen‘s post-Justice League activities.
Barry Allen may be seen dressed in his Justice League outfit in a few panels from the forthcoming prequel comic for The Flash. We see its disintegration here, which may help explain why he has a new suit in the future solo feature:

Barry Allen‘s new outfit was created by none other than Bruce Wayne, according to The Flash director Andy Muschietti, who made the revelation at DC Fandom 2020. The more streamlined outfit is a change from the armored appearance we saw in Justice League and might give the Scarlet Speedster a more nimble appearance when using the Speed Force.
The Flash is slated to come out on June 23, 2023, as of right now.