You lost me here.
The reason the lower keys are easier to heal has nothing to do with the affixes and more to do with the fact that people don’t kick, stop, dodge mechanics, or use personal defensives in lower keys. Instead they herp derp along and the healer picks up the slack. You want to kill healers desire to play? Implement this “solution”. I’ve healed for 20 years. I love healing keys.
I would just flat quit if this crap was implemented.
“Meta” is a community issue up to a certain point. There will always be a meta in the sense of class XYZ does 0.01% more dmg than all the others thus it is the best, but in keys there hits a point where survivability and utility play into it just as much as dps does. Not all class kits are built the same.
Careful what you ask for. Blizzard’s idea of “fun” is forcing the players through agonizing and asinine hoops; they are very much “out of touch” when it comes to the F word. Affixes should have been “fun” from the start. They should have been buffs to the player that help as the keys scale in difficulty. Instead, they were just obnoxious bs caked on top of the 900000 mechanics designed to try and combat weakauras.