There is little doubt that Suicide Squad is going to be a dark movie. Centered around a group of super-villains who are tasked with an almost-certainly suicidal mission, and featuring Jared Leto's debut as a "powerful and menacing" Joker, the movie's trailers have made it clear that it is not a movie aimed at kids.
In light of Deadpool's success, then, Suicide Squad would make the most sense out of any DC universe movie to follow in its footsteps with an R rating. After all, even Batman V Superman: Dawn of Justice will be seeing an R-rated release on home video. However, it doesn't appear that any such ratings change is in the cards.
Speaking to Collider, Batman V Superman producer Charles Roven, who is also involved in production of Suicide Squad, said that Warner Bros. has no plans to limit the potential audience with a more adult rating:
"At the moment, my understanding is we are still releasing Suicide Squad as a PG-13, so there hasn’t been to my mind a serious conversation about doing anything other than that. I understand why Deadpool was released as an R-rated film, and I think that the DC Justice League characters, particularly because so many of them are so iconographic, have been around for so long and for so many generations that have grown up with them, and that are still growing up with them, I think we want to present them, when we finally present them, to the broadest possible audience that we can. I think that’s why we’ve planned on making these movies PG-13.
"I’m not seeing any real reason to change. We’ve made some pretty edgy films that are rated PG-13. You never want to say 'never' because we all evolve, but right now I think we’re staying that course."
What about other, lesser-known properties from DC comics, though, such as Lobo? Roven replied that that's not really his field of expertise:
"I am a fan of other DC characters that I’m not producing those films. Right now my focus on the DC Universe is the DC Justice League Universe... There’s a group we’re maybe kicking around the idea of it. We haven’t actually yet fully put it into development so I can’t really talk about it, I’m sorry. But at present, for the time being, we’re headed down this course."
That leaves the possibility open for other DC franchises to hit the big screen with an R rating, including whatever group Roven was alluding to. While it makes sense for Warner Bros. to keep the main, tentpole franchises PG-13 in order to make them marketable to as broad an audience as possible, some of the more niche properties might benefit from catering to adult fans who want to see movies geared toward them.
Batman V Superman: Dawn of Justice opens on March 25th, 2016, followed by Suicide Squad on August 5th, 2016; Wonder Woman on June 23rd, 2017; Justice League Part One on November 17th, 2017; The Flash on March 16th, 2018; Aquaman on July 27th, 2018; Shazam on April 5th, 2019; Justice League Part Two on June 14th, 2019; Cyborg on April 3rd, 2020; and Green Lantern Corps. on June 19th, 2020.