It ended up the exact nonsense that was predicted. Mitigation is king and bosses don't need that much healing, making the extra raw heal power of a "Pure" healer mostly irrelevant. So in reality the divide looks like this.

Healer with nothing else.
Healer with mitigation and shields.

Easy choice.
AST and WHM hang in there mainly because 99% of content is just irrelevant and any healer works fine. AST also brings mitigation and CU/Neutral are extremely good, not to mention Macro and Star are just OP to the point of carrying mechanics. But it's not good because you need a Pure Healer. It's good because it's OP and has enough barrier for endgame.
WHM is just WHM. They should just make it a limited job at this point for Normal mode content.

As predicted too, SGE/SCH is a ridiculously good comp in the hands of a decent team. It would easily be top if AST wasn't OP.

The only thing the shield/barrier split has done is discouraged AST/WHM comps in the harder content. That's literally it.