I imagine world first meta won't run AST/AST but midcore meta can potentially run AST/AST since mitigation stacking won't be as big of a thing due to usually on-par ilvls with content.
In the end, I think what will determine AST/AST versus SCH/AST is if super stacking every DPS buff under the sun will lead to a higher net gain versus the high Expanded Balance uptime of AST/AST for more consistent damage over the course of the fight.
That or we all end up wrong and the meta somehow becomes WHM/WHM due to high non-mitigatable effects in the raid. LOL *Looking at mechanics that constantly do 80% of max HP damage attacks*
That'd be a ironically funny and scary thought if meta somehow became WHM/WHM. Highly unlikely, but amusing.
The fairy channel - I'm wondering if the fairy starts with a charge when summoned since gaining fairy charge normally seems like a slow process (effectively 30 charge every minute). If it starts with say 60 or 70 charge upon summoning, we may see a Dissipation hitting play more frequently to optimize fairy resummoning.
[edit] I will admit that my thought process and opinion may be biased since I never thought I could get so salty about healer balance but here I am. Not trying to be purposefully stubborn and if I come off as short and abrasive, I apologize.
I didn't think S-E could mess up healer balance anymore than it already has but here we are and it's put me in a very... growly spot. lol.