the biggest issue i notice, is this was the unique play mechanic of conjurer and thaumaturge.
almost certain that they are not going to allow cross class jobs to use aga version of mage specific spells I would not worry about that part. They will make them job specific. I think removing aoe toggle also allows them to further define what a CON vs THM is rather then the only current distinction being CON gets a crappy AOE circle where THM gets a monster cone.

ie, a CON can now get CURAGA III where a THM might only get Curaga-I. Allowing CON to be further developed into a main healer and THM being a more effective enfeebler type mage.