First things first: looks like JK Simmons has stuck the landing in his jump from Spidey supporting cast to Batman Family, if this pic tweeted by Justice League director Zack Snyder is any indication:
That Gordon looks right out of the Denny O'Neil/Neal Adams era of the character and, not to be sucked in by production design, it's certainly an encouraging image.
Whatever your thoughts about Batman v Superman: Dawn Of Justice, you couldn't have walked away from that film without at least a hint of curiosity about this universe's version of Batman and his surrounding mythos, and Commissioner James Gordon is a pretty good barometer for such things. On the 1960s TV show he was a completely emasculated desk jockey (played by Neil Harrington) who couldn't get to that red phone fast enough whenever a riddle or clue turned up in his mailbox. Tim Burton had similarly little use for the character, filling the role with a reliable character actor (Pat Hingle) whose main repsonsibilities were to point and yell dynamically during Dutch angles, and to unveil the Bat-Signal in the 1989's film's closing moments.
But now we're a generation raised on the post-Miller Batman mythos and, whatever else his crimes, Frank Miller helped make Commissioner Gordon a flesh and blood character, turning the cop's relationship with Batman into the emotional linchpin of the whole thing. That manifested nicely in Christopher Nolan's Dark Knight trilogy, and in many ways Gary Oldman's take on the character was the most interesting/human element of that series (for two films, at least).
One of Snyder's tougher tasks has been (and continues to be) to push away from the Nolan era and carve out a space for his take that feels both "new" and "correct." This visual of Gordon feels correct; I'm expecting the "new" part to kick in when JK Simmons starts talking.