So this happened.
Without a Vancian magic system you end up with a bunch of underpowered sorcerers running around spamming underpowered spells. It takes all strategic planning out of a magic system and turns it into a purely tactical one. Some people like it but I always thought it was lazy design. It also tends to lead to a spell progression where you upgrade your spells as opposed to getting new spells. Also lazy. The sheer number of spells in BGT is astounding and choosing which ones to memorize and when to use them was a ton of fun.
And hello mana pool!
I suppose this was expected when they talked about the soul thing. Of course I’m just speculating as nothing official has been announced.
Anyway I'm just bitter because I really like IE magical combat and I think a game made in their image should have the same basic magic system. But what do I know.