You can argue all you want that Elliott and Mary Drake aren't "A.D." In some sense, you'd be right; we can't really confirm or deny. That said, these two seem like they're up to no good. Here's everything they've done so far: Dr. Rollins has married Ali under deceptive pretenses. Rollins and Mary Drake disguised themselves as the corpses of Detective Wilden and Jessica DiLaurentis respectively, with the primary goal of sending Alison into a full-tilt meltdown. Elliot has seized 51 percent of the Carissimi Group, since he's married to Ali. Mary has taunted Spencer and abducted Hanna. Dr. Rollins has injected Alison with something that can't possibly be good for her.
