It is simple. If Blizzard decides that this is an exploit then they'll find a solution which has no impact on the vast majority who sit through four events and move on to the next invasion. It would be downright stupid for them to take what a fraction of players are doing and stamp a "one size fits all" nerf because some folks are leveling up quicker than others in an event which has been already tweaked to death to fulfill such a purpose thanks to their scaling tech.
Until Blizzard comes out and says that this is an exploit then the backseat moderators really need to put their pitchforks down until it's either acknowledged as such or no one gives a shit anymore because we'll be in Legion.