You missed the part where SCH's basic, GCD healing recieved a nasty nerf in a massive MP cost increase at 4.0, and Aetherflow's MP recovery was severely cut down from 30% to 10%, so this "buff" is actually bringing SCH back up to the level of AST and WHM. Basically, 4.0 way over nerfed SCH, and it's getting little buffs to find the sweet spot.

ALSO, Astrolgian sects give ALL healing spells better potencies without increasing MP costs, so AST heals are comparatively cheaper, and you have the short, potend oGCD Essential Dignity and can store a Lady of Crowns. ALSO ALSO, you have Lightspeed as a clutch heal situational skill that slashes MP costs on top of Lucid Dreaming and Ewer.

Yeah, man, AST isn't hurting and won't be set aside by tye meta after 4.1.