As Silverdan7 usefully pointed out plyos are a specific type of explosive movement.
Plyos may have a place in training lower body movements where there is a eccentric contraction rapidly followed by a concentric contraction as in sprinting but I wonder where this is duplicated in most upper body movements.
As opposed to just training explosively do any upper body movements need an eccentric contraction, short resting phase and rapid contraction or do they add something which regular explosive training does not?
Possibly receiving the force of a charging opponent and throwing him off may be an example but I am not sure that the action is quick enough to qualify.