Do many classes really have a big selection of AOE stuff to do?
Just looking at before level 52 most classes only get like one spamable thing and an oGCD or occasional action. DRG just has Doom Spike now with oGCD DragonFireDive, Ninja can only spam daggers with an occasional mudra. WAR is overpower and maybe a steel cylcone, PLD is flash and Circle of Scorn. Hell even DRK only has unleash and Dark passenger at this level.

I guess Monk gets to still do a rotation with Arm of the Destroyer and RockBreaker.
It's not like BLM or SMN have complicated AOE rotations, if they maybe get an extra button compared to the above stuff.

So maybe they could move Contre Sixte to a bit lower level for consistency? It's all pretty inconsequential IMO.