Well the vit requirement seems to be suggested to prevent people from switching from a def set to an attack set in one click (not entirely baby steps~).
So I doubt class restrictions will help cause
initially everyone had em - sins/wiz are too op pls nerf
then everyone but sin/ wiz had em - seekers now too op pls nerf
so in a hypothetical scenario where its class restricted to bm barb ep myst - (2 weeks later at the max bm barb ep myst too op with def camp pls nerf)
So vit restriction so they cant switch too often, granted it makes you less tanky in masspk but hey its the age of scripts someone will figure out a new thing to camp