With the next declarations regarding Endwalker, SE had stated that healers will be split into pure and shield healers.
Fundamentally, healers were thematically put into these two categories since the beginning, but reviewing the actual skills the three healers we currently have got, there was one thing which became clear to me: We actually don't have a split as things stand right now.
WHM has Devine Benisin for a powerful shield on a 30s CD (which is better than non-crit Adlo, and comes more than often enough for any content) along with Temperance, which is basically Sacred Soil before ShB's buff. AST has Celestial Intersection for a free succor level shield even during Diurnal Sect, and Neutral Sect to be both a pure and shield healer ever two minutes.
Alternatively, AST has the same skills that allowed it to act like Dianural while in Nocturnal Sect, and SCH had gained a powerful regen on a stick in Sacred Soil, Indominability and Excognition for powerful raw heals, Whispering Dawn for a decent regen, and Fey Illumination for a healing buff, and that's on top of Emergency Tactics that simply turns Adlo and Succor into raw healing, with a 15s CD so that it's available every time you need it unless if you want to use it twice back to back to solo save a DRK who just used Living Dead.
With SE's declaration of having two pure healers and two shield healers, I think they should really double down on this idea. As things stand, we didn't really have this dichotomy since as early as HW, but if it's done well, I think it could be really interesting, though the two pairs would need to be distinct from each other.
Though some would complain that double shields would still be unviable in raids, I don't think it's an issue. Changing jobs to match raid comps isn't really a new, or bad, thing. As long as a strong meta doesn't get developed at least.
So, with the...success...that WHM has gotten with its changes in ShB, I think the first thing would be to define how it works.
WHM should draw mainly from two aspects, the pure healer role, and its lillies. First, it's oGCD heals should be entirely stripped, aside from Bene as an emergency heal. All of its regens should be stripped as well, as to why, I'll explain later. From there, its GCD heals should generate blood lilies, and more than one could be stocked. Regular lilies could be used to empower the GCD heals, like next heal has double potency. Glare and Afflatus Misery should be roughly comparable in damage in regards to consumed GCDs(technically, the existing potencies already allow for that), so that healing won't be a DPS loss for WHM.