Place pork in a 3-qt. slow cooker. Pour root beer over top. Cook, covered, on low 2 to 2-1/2 hours or just until tender (a thermometer inserted in pork should read at least 145°)., Meanwhile, in a large bowl, toss slaw ingredients. Refrigerate, covered, until serving., Remove tenderloins to a cutting board; let stand, covered, 5 minutes. Discard cooking juices., Coarsely chop pork; return to slow cooker. Stir in barbecue sauce; heat through. Serve in taco shells; top with some of the slaw. Serve remaining slaw on the side.