Pfft, no. Genard way the singer, has expressed how he dislikes emo. The band MCR before they broke up, took more of a rock and roll vibe, like the band queen basically. So no, they were not an emo band.
Is MCR an emo band?
Music itself in general a haven for emotional refuge. People are in need of daily dosage. Some bands lift them and some down them. At the end of the day everything is emotional roller coaster ride. Some lyrics are well pronounced and some merely touch the fringe.