I think back in legion beta, frost did have some kind of AOE "soul attack", not sure if we had it while we also had remorseless winter or they simply changed the soul theme to the current remorseless winter "cold theme".
Also I am wondering if they will carry over frost's passive/very boring artifact trait come BFA. They said some classes/specs would carry, I wonder if frost is one of those classes/specs. Yes it is boring and incredibly dull but free damage is free damage.