It does make sense from a design standard that tanking was simplified to make the role easier to use and inviting to others. However, I would argue circle AoEs for tanking does more harm than good even if the Overpower change was for the sake of consistency. Conal AoEs, while can be tricky to aim initially as well as targeting being sliiiiightly finnicky, does have the advantage of a longer range in front of you while can help with positioning mobs away from the party. With a circle, you are losing 3y in front of you with wasted 5y from the back when you position it and the only way to take full advantage with that is to center yourself in the mobs (although it does work fine with fewer mobs but not so much with bigger pulls). If every role had circle AoEs, it's alright to do despite the enemies will be in different directions attacking the party with the bad, but they don't and that can cause grief. This is one of the reasons why I played WAR over the other tanks because I prefer using cones and now I'm forced to use only circles.
Not to mention DNC, for example, is the only physically ranged DPS without a spammable cone AoE so this change just doesn't make any more sense to me imo.