True. But, it wouldn't set up events for Civil War to pit hero against hero after what happened.
It would depend on several factors. For the most part, DC has kept a tight wrap on what exactly all the plot entails. There are just so many things which don't make sense. Batman pretty much having given up the cape and cowl, only to fight crime through use of drones. Waller using the Joker in the Suicide Squad movie to draw out Batman. Lex Luthor manipulating both Batman and Superman into fighting each other. Superman killing Zod.
As it stands now, Deadpool is being released on Febuary 12th 2016. Divergent: Allegiant comes out on March 18th. And Batman vs Superman on March 25th. Plus a few other movies. It will be close especially if Deadpool carries over in the top three spot for at least three weeks. Even when Dawn of Justice comes out, there is also word of mouth. If it is not good, people won't go to see it after the fourth week. Granted, they could still do over 300 million total worldwide, but doubt it would come close to what some of the marvel movies have done.
Mini Update: According to a website, Cyborg is also in Dawn of Justice played by Ray Fisher. It is also reported that Cyborg will have his own movie in 2020 as well as appearing in the Justice League part one movie.