The Cowboys filed in court a declaration of support of the NFL Players Association's emergency motion for a temporary restraining order or preliminary injunction, fighting the six-game suspension levied by the league against Zeke.
I'm not sure what else is expected of JJ at this point as this is now an issue between Zeke/NFLPA and the NFL. JJ was very vocal in his convictions of Zeke's innocence but now that the situation is in the courts, he most likely is being advised to stay quiet.
http://www.espn.com/nfl/story/_/id/...support-emergency-motion-ezekiel-elliott-case