From what I remember, AOE is either Area Of Effect, which means a global spell. If thats true then Life DOES have one, Sanctuary, or it means All of Enemies or something, which means a target all spell, which Life also has 2 of, but they heal their side and don't target the enemies. Either way, however, I don't think we'll get more spells in Celestia for the current schools, because it would mess up the "Master of (insert school name here)" badges.
AOE as in "area of effect"? If you mean a healing spell that affects all the wizards on your team, Unicorn and Rebirth do that. If you meant something else, I don't know.
AOE means area of effect and I believe the OP (original poster) is speaking of a life attack that will effect all the enemies.
I have a life wizard. Just a few days ago I was helping someone defeat Malistaire. As we neared the end and was fighting the undead servants before Malistaire ( I can't remember their names), I thought of what the results would be if life had an attack all spell at that moment. The death enemies (who never shield) would never stand a chance. As it stands now, I believe adding an attack all spell to Life would overpower it. Yes all the other schools have AOE spells, but they do not have the healing power of Life, they also have to put up with the opposite school enemies shielding against them. That is something we of the Life School do not have to contend with unless of course we are fighting balance, and even then we get a boost and the shield is only 50%.
Maybe as the spells get more powerful as do the enemies, Life will get an AOE that will attack all enemies.
Hannah Lifebringer Level 50 Life
P.S. on test realm before the Selena Gomez update, I noticed the Seraph card said damage to all, but it did not have that effect. Maybe there will be a change.