Worked through this in another thread: it is not a nerf. In theory.
Blizzard’s statement is that they are concerned that damage is getting too spikey, which results in some healers being very strong because they are equipped to respond with spike healing and put the party back to full very quickly, while other healers trickle feed and leave the party below 100% for too long - at which point the next heavy damage event is lethal.
The stated intention is that they will reduce the damage spikes while also increasing player hitpoints and damage taken overall. Their goal is that healing becomes more of an over-time effort, rather than reaction testing the healers, expecting that the party is always fully topped between damage events, and demanding that the ramp healers have already ramped up for several GCDs before the damage phase begins.
In theory, this is beneficial, because the trickle-feed specs won’t struggle to respond to sudden bursts, and the ramp specs won’t be so reliant on watching timers to know when to start ramping. It will make it less important about how that healing is delivered, and more important that lots of healing is done. All Blizzard have to do is ensure that hps output is about the same and worry less about whether that healing arrives in bursts or trickles.
So on the whole, this is a positive announcement - although I think they explained it poorly.
Do I trust Blizzard to balance it all out, having announced this change just 2 weeks before it goes live?
No, not at all. They did exactly this in very late beta, at a time when all youtubers were saying how healers were nicely balanced and all felt good. A big 40% increase to player hp and damage taken, and suddenly it revealed that dungeon hps wasn’t at all equal it’s just that all healers had been delivering massive excess. Now they weren’t and we ended up with a strong meta ranging from S to D tier.
It did get mended over time, with patches after launch adding new talents and effects to the healers that were struggling with the burst damage such that right now, they’re all in a fairly good place and if you aren’t looking to push 25+ keys you can play anything. It did end well and I applaud the ongoing tuning and patches as a very very positive thing indeed - but I haven’t forgotten nor forgiven the rocky launch any more than I have forgiven or forgotten the state of imbalance in 9.0.
If this 25% change had been announced 6 weeks ago, I’d have been much more optimistic. On the whole it is still a good change, but I do not have much faith that 10.1 will actually be balanced on launch with the timing as it was. It will settle over a couple of months and be of overall benefit, but I do think we should buckle up and expect the usual candidates to get locked out of pugging while the meta healers get all the attention.
Side note; I’ll be starting 10.1 on preservation evoker with resto shaman backup, because I am so tired of finding myself at the bottom of the tier lists. It is demoralising, and it can cut the legs out from under you to have a slow start to a season because pugs prefer someone else.