Well, according to http://parts.yamaha-motor.com/ - their parts list for the banshee & warrior rear caliper assy's shows that they use the same caliper, part number is identical anyway...
banshee 5 1UY-2580W-00-00 CALIPER ASSY, REAR 2
warrior 5 1UY-2580W-00-00 CALIPER ASSY, REAR 2
So I would say...Yes, most definately.