Speaking theoretically, the DCEU having a ceiling of $350 million domestic and over/under $1 billion worldwide would be a very great thing indeed. But if they were mistaken to presume that Batman + Superman + Wonder Woman = $1.25-$1.6 billion on concept alone, then we may be just as mistaken to believe that a moderate course correction for Justice League Part 1 will then make up that extra few hundred million bucks.
Maybe the DCEU, in its current form, just isnt going to end up among the top-tiers of franchise filmmaking because it was never going to. Not every would-be blockbuster hits $1 billion globally. This isnt remotely the first incarnation of Batman or Superman that weve seen onscreen in recent years. Regarding comic book superhero movies, Dawn of Justice is still near the top of the pile.