I had that happen the other day. Evoker wasn’t moving so I just let him drop. Like i can heal a lot of things but I can’t out heal bad play 
Oof. As a prevoker main other lizards who don’t Hover enough hurts my soul.
This is why people think drac players are idiots!! 
I dont think Disc is getting buffed, nerfed a less raids but break even in M+
Prior
Do 100 damage,
Raid: Attinement 40%, so 40 healing
M+: 40X 1.5 = 60 healing
Now
Do 100 damage
Raid: 35% so 35 healing
M+: 35 x 1.7 = 59.5 healing
So overall, raid nerf with no real change in M+ healing. If math is wrong please let me know.
Regardless of nerfs, people are still completing keys way above 20.