From what I can tell, based on the fact that WHM is often referred to as a "Pure Healer" because it has limited shields (Only Divine Benison), that it was mentioned that SCH was getting more direct healing skills and that WHM was noted for getting a new DPS options.

I think that this statement of becoming "Pure Healers" simply means they're downplaying or outright removing Shields (Or "Barriers") from the main healing skills.

What this will mean for SCH and Nocturnal AST?

Well, I think that SCH will likely still have some form of CD that provides a shield, to mix with their Tactics spells. But otherwise, they'll probably have some more focus on direct healing, likely involving Lily being their version of Regen in lieu of you know, actually having a HoT spell.

Nocturnal AST? Maybe won't suck now xD I don't know what they might be doing with it though, since they can't just remove it as it's needed for their Role Job quest. But I'm betting it'll be moving away from providing shields and maybe might affect something different about their heals.

But yeah, not sure how "Offensive abilities adjusted" is going to work out but who knows. Maybe it's something like having a slightly more interesting rotation than "Stone/Malefic/Broil x Infinity". Maybe it's some more damage, putting Healers a bit closer to that of Tank DPS. Maybe Scholar will get Broil before level 54 and so not suck absolute butt while leveling.