Moreso that the thread happened because, after several years of giving feedback about the Healer role's... role? in party content being usurped by other roles (mainly Tank), and forcing us more and more into 'Press spam filler action for damage, because you can cover all healing with OGCDs', the people giving the feedback were told, time and again, 'just wait till DT, they'll make healing harder'. Then the media tour showed that literally nothing had changed about how healing worked, that WAR could still effectively solo, or keep the team alive because Nascent Flash is an abomination in the face of sensible game design principles, and so the camel's back broke for a lot of players
The other issue is, yes Xeno does Ultimates and Savage. But doing Ult/Savage is not a prerequisite for being able to do a 1T3D run of EX roulette. As long as you can manage to target Nascent Flash onto a DPS when you press it, almost anyone is able to pull it off. It's not some heavily skill-dependent test of your gaming capabilities, it's 'target ally before pressing the funny instant-full-HP button'
We could, but my point is, if you're a healer that wants to have more damage hitting the party, and therefore more reasons to press healing GCDs, Stormblood had that (due to having less OGCD access).
If you're a healer that says 'we will always end up having to DPS in downtime, and there will always be downtime in some form in any content, so make the downtime more interesting by adding maybe 2 more damage buttons to our 'rotation'', then Stormblood had that (eg SCH having more than one DOT, and the timers of said DOTs being staggered)
Yoshi-P said, in a pre-Endwalker Live Letter, that 'we don't plan to return to the level of complexity that 3.0 had'. You know what else didn't have 3.0's complexity? 4.0, Stormblood. No matter how we slice it, it seems like Stormblood (with adjustments/lessons learned from SHB onward, eg WHM Lilies) is the ideal 'blueprint' to start rebuilding from
edit:
I think that their opinion is important to keep in mind, at least in some regards. A lot of their stance does seem to trend towards 'keep the status quo, because change is scary'. But that can be addressed by having the main core of the Healer jobs be effectively identical to how it currently is, and the additional complexity for those asking for it, would be an 'optional' addition on top.
For example, I've posted about how I'd rework the Healers. Let's take the SCH, as an example, because Striker responded to that one in particular. They mentioned that they'd dislike 'being forced' into the 'stance dance' gameplay that the Strategies, Offensive, Defensive and Emergency, would provide to the player. In response to that, I reworked the potencies of actions, such that Strategy: Offensive has identical healing gameplay to the current DT SCH, with equal (or sometimes stronger) potencies to DT SCH.
As such, a player like myself would find more enjoyment from the job, due to having a lot more choice in how to handle situations. Rather than a Succor, I could use Defensive-Indom for a barrier instead of healing. I could Defensive-Excog someone, which applies a barrier to them, and then Deploy both that barrier AND the Excog to help heal after the raidwide. I could forgo barriers entirely, and stay in Defensive so that Lily (the fairie) applies barriers to everyone over time via Embrace. But a player like Striker, may prefer to simply ignore the Strategies and focus on playing like they currently would. By staying in Strategy: Offensive, they'd be effectively playing 'Dawntrail SCH' automatically, and would still be able to clear all content.
It's fine to be worried that changes will make a job you like, into a job you don't. The RNG removal for AST killed that job for me, for example. But the difference is, the AST changes were something that everyone was forced into. Even I have to deal with the cards being 100% predictable and the lore being demolished for a third time. But the path above allows players who don't want to partake in the changes, to ignore them completely, which I think is far healthier for avoiding players getting into a tizzy about 'oh I'm forced to do XYZ and I picked Healer to avoid that'. You don't want a 'full DPS rotation' (read: applying 3 DOTs and pressing Broil in between refreshes)? Sure, then simply don't press the DOTs, because the potencies are such that simply spamming Broil on every GCD is 98% of the damage of making perfect use of the DOTs