Keep in mind there is a spell that allows these Mage companions of ours to revive the fallen, a HEALING spell, and a very advanced one.
We can learn that advanced spell, but not a simple one?
I believe so.
In DA:O a mage had to learn Heroic Offence, Heroic Aura and Heroic Defence in order to learn Haste. In DA2 a mage had to learn Heal and Heroic Aura.
In DA:O a Mage could learn Walking Bomb at lvl 1. In DA2 a mage had to learn Spirit Bolt first.
In DA:O mages could learn Flame Blast before Fireball. In DA2 they learnt Firebal straight off the bat.
What does this and the school restrictions in DA2 show us, other than gameplay design is constantly changing?
From a lore perspective it shows that paths to magical capabiliy are not linear, nor fixed. Its perfectly viable and has precedent that what some mages consider a higher level spell can be grabbed by others with less effort, but other lower level spells may be competely unobtainable. Look at my Haste example.