Tbh considering how AST is the busiest healer, I'd say it's the most likely one to align with the "pure healer" mentality the devs want to keep, specially since their buff spam already compensate for their weak damage, whereas SCH and WHM (specially WHM) have more than enough time to go for a green dps style. Who knows, maybe sage will be to healers what GNB is to tanks /shrug