Noct AST has always felt like superior SCH. Any time you need shields you have them on demand while retaining some of the best HPS in the game. You even have better shields than SCH in the form of a triple shield from swapping sects at the start.
Any time you need regens you have them on demand, you only need to swap sects, not even classes.
Diurnal AST has always felt like the speedy verison of WHM to me at the cost of chunky heals but it will never replace WHM, SCH on the other hand... 700 potency instant shields are just too good especially when you add their entire kit on top of it.
The removal of Nocturnal AST will allow them to properly balance the shield healers so it doesn't always feel like "Do I want to deal with cards and play the superior healer, or do I want to play the inferior healer but not deal with cards..."
The only thing SCH has on Noct AST is mitigation because Sacred Soil is busted AF. You can consider Whispering Dawn comparable to Star but they both have their own merits.
Also Neutral Sect shits on Seraph. God I will miss Neutral Sect that ability shouldn't be allowed to exist.