Justice League has been officially rated PG-13, and it's also been confirmed Zack Snyder will indeed receive sole directing credit on the DC superhero team-up blockbuster.
Justice League is the followup to Snyder's Batman V Superman: Dawn of Justice, and sees Batman and Wonder Woman form an alliance with Aquaman, The Flash, and Cyborg to take on Steppenwolf, an alien warlord who's arrived to conquer Earth in the wake of Superman's death. An incredibly important film for DC's burgeoning shared cinematic universe (but don't call it the DC Extended Universe), Justice League endured a troubled production, as director Zack Snyder departed the film's production in May following the tragic death of his daughter. Avengers director Joss Whedon - whom Snyder had already brought on board to fine tune the script - took over directorial duties, overseeing the film's reshoots and post-production. Rumors have swirled for months over how much of the film Whedon was altering, and if the changes were so significant that perhaps he and Snyder would share directorial credit.
It seems that's not the case. Justice League's official website has Snyder listed as the film's only director. It also confirms the film's rating, which to the surprise of no one is PG-13. The PG-13 rating has essentially become the default for wide release, big budget blockbusters, promising more visceral thrills than the children-leaning PG rating, and promising parents it won't feature the graphic violence and sex of an R rating.
But the real news here is Snyder's credit, and Whedon's lack of one. This really shouldn't be a surprise. Given the unfortunate personal circumstances, it seems unlikely Whedon - who's been uncharacteristically quiet about his involvement with the film - would even want the credit. And even if he did, the DGA's rules would have made that a difficult prospect.
Still, it seems unlikely this will end debate over whose film Justice League really is. Gal Gadot has downplayed Whedon's involvement, while Ben Affleck has suggested the film is a genuine product of two directors. Whedon is still credited as a co-writer of the film's screenplay, so his contribution is being acknowledged, though perhaps not on a scale commensurate to the work he's put in. It's entirely possible we'll never really know how much each man contributed to the film, but it's clear at this point that virtually everyone involved is sending the same message: Justice League is Zack Snyder's film.
Source: Justice League Official Site