10 New Things We Learned About Joss Whedon's Justice League
7. Diana's "Age Of Heroes" Remark Hints At A Massive History
Despite only being about four years old, it's clear that the DCEU is sitting on a rich history, owed in part by the aforementioned decision to make Batman a distinctly older character in this universe than what would usually be the case.
During a conversation with Bruce, Diana remarks how "the age of heroes would never come again", to which an oddly optimistic (or perhaps urgent) Bruce replies, saying that "it has to." What this bodes for the DCEU is at present unclear; it could be referring to Superman's early arrival onto the world, or - perhaps more likely - it could be referring to a time when Batman was his younger self, living in a world populated by older heroes where vigilantism and super-heroics were the norm.
It would make sense if you were picking up strong Watchmen vibes from that exchange, especially since DC have dealt with the same themes that Alan Moore's storyline broached in books like The New Frontier. If this is the case, and an 'Age of Heroes' was a thing in DC's onscreen history, then it could be a hint at the Justice Society of America, a postwar team that preceded the Justice League by some time in the comic books.
It'd be pretty amazing to see DC acknowledge their past in such a way, particularly if characters like Jay Garrick (the first Flash) were given a nod in the process.