When canceling the PlayerMoveEvent, the direction of the location of the player set back to the vector (0/0/1). Therefore, the player is forced to face south, no matter where he looked before, which is obviously horrible for most circumstances when you just wanna block all of his movements, but in another direction.

Attached is a simple plugin, based on 1.13.1-R0.1-SNAPSHOT, to toogle the cancelling of this event by command "cancel".