User blog comment:Deathmanstratos/Call of Duty: Ghosts to have Dedicated servers on all platforms/@comment-4778612-20131007234610/@comment-68.189.244.82-20131009030142

I don't remember them saying it was "impossible" for PS4... I remember them saying Xbox got them because of the Cloud, and they were looking into ways to bring dedis to the other platforms. It admittedly didn't sound too optimistic at the time, but it sounds like they figured something out.