When GREEN LANTERN flopped, WB scrapped those plans.
GREEN LANTERN 2, which featured Hal Jordan rallying the Green Lantern Corps to face Sinestro and the Sinestro Corps, was entirely scrapped, nearly sinking Reynolds' career in the process, while THE FLASH, which featured Barry Allen facing off against his mother's murderer, Eobard Thawne, a time-travelling speedster who became stranded in the past after a failed attempt to kill Barry as a child, and engineered his accident as part of an elaborate plan to return home, provided the basis for the popular CW TV show.
WB briefly tried to revive the JUSTICE LEAGUE project once again in 2012, after THE AVENGERS broken box office records, with a script written by Will Beall in which Superman, Batman, Wonder Woman, Flash and Green Lantern join forces to fend off Darkseid's invasion on Earth. However, the script was reportedly so subpar none of the directors they approached for the job, among them Ben Affleck, were interested.
Simultaneously, WB was facing a potential lawsuit from the heirs to Superman's creators Jerry Siegel e Joe Shuster that could cost them several pivotal elements of the mythos. One of the ways to avert it was getting a new movie out ASAP. They scrambled to get a script in order, and after getting multiple pitches from numerous scriptwriters and comic book writers, Nolan brokered a meeting between Goyer, who had co-written THE DARK KNIGHT trilogy, and the studio heads to pitch Goyer's draft, MAN OF STEEL, with Nolan agreeing to produce.
The script had issues, but it also had to enter production before deadline. And Zack Snyder proved himself to be the right man for the job by burning through shooting fast ans easy and willing to play ball with the subpar scripts whereas other candidates like Darren Aronofsky and Duncan Jones would take too much time trying to get it right.
And thus came MAN OF STEEL, and the DCEU was born... For better or for worse.