Batman v Superman: Dawn of Justice, when it hits theaters on March 25th, will carry a PG-13 rating. As of yesterday, the MPAA announced that the film's subsequent "Ultimate Cut" home release will be rated R.
While it isn't specifically known what's different between the two cuts, the ratings board signifies that this particular cut's rating is due to "sequences of violence".
This wouldn't be the first Zack Snyder film to get a director's cut/ultimate cut for DVD/Blu-ray as both Dawn of the Dead and Watchmen received lengthier editions with additional material. The Director's Cut of Watchmen particularly strengthened the latter.
While I'm sure many will assume that this in response to the success of Deadpool, it's likely that this cut of the film had been submitted long before Fox's effort completely upended expectations. In reality, this is more par for the course with Snyder's entire oeuvre.
It's worth noting that superhero films have had to work to be rid of R-ratings before, given their proclivity towards violence. Joss Whedon's Avengers had to submit three cuts before it could shed its R rating. It's less about the violence itself and more about blood presented, which is why in The Dark Knight, you see people get shot and killed but you never actually see much blood. For example, who can forget William Fitchner lying awkwardly crumpled on the ground after getting pumped full of bullets by Heath Ledger's Joker?
We won't know what's likely to be expanded upon, or added back into the film (say, a rumored Jason Todd flashback, if I had to spitball) until we see the theatrical cut next month. But regardless, what's being presented in theaters is in line with every other recent superhero offering we've seen thus far, if the rating is any indication.