As seen in a few pictures that have already circulated on the internet, there will be a superhero appearance in the upcoming Suicide Squad film. Batman, who will be played by Ben affleck, will be seen in the film. Other than Batman, there have been rumors that Henry Cavill's Superman will also make an appearance in the said film. Sadly this rumor has been proven false. In an interview with Metro, Cavill said, he will not be seen in Suicide Squad. However, although Superman won't be seen in Suicide Squad, his presence will be made felt. In the San Diego Comic-Con footage, Amanda Waller is heard speculating that Superman's public debut acted as some kind of "beacon" for the super powered and specially talented to emerge from the shadows. Warner Bros. has maintained from the start that a filmmaker-driven approach is what they are striving for. And that's what seems to be happening here. Warner Bros. hired Ayer to tell the best possible Suicide Squad story on-screen, and the narrative he came up with simply does not require a scene or two with Superman. That Kal-El isn't in the film should be comforting for fans, as it shows the studio is serious about letting their directors work somewhat independently within the larger sandbox of their blossoming franchise and craft compelling films.

While Marvel brings out new heroes to the cinematic world, DC is putting up a fight with these upcoming movies. Batman V Superman: Dawn of Justice opens on March 25th, 2016; Suicide Squad on August 5th, 2016; Wonder Woman on June 23rd, 2017; Justice League on November 17th, 2017; The Flash on March 23rd, 2018; Aquaman on July 27th, 2018; Shazam on April 5th, 2019; Justice League 2 on June 14th, 2019; Cyborg on April 3rd, 2020; Green Lantern Corps on June 19th, 2020.

Sources:

https://www.cinemablend.com/new/Henry-Cavill-Reveals-Whether-Superman-Shows-Up-Suicide-Squad-78677.html