Blizzard has been trying to tone down Mercy's toolkit for a while now, and there are more changes to contend with as of today's Overwatch update. The nerfs-in-testing have surfaced in the live game.
Fresh off the PTR, her ultimate ability Valkyrie no longer makes Resurrect instant and it also doesn't grant another charge of Resurrect. What's more, the speed boost to Guardian Angel has been decreased by 50 percent and Valkyrie now runs for 15 seconds instead of 20 seconds like before.
"Mercy's recent Resurrect changes have helped in allowing enemies to have more counter play in dealing with her, but she was able to use Resurrect through Valkyrie enough to largely mitigate the impact of the previous changes. Additionally, we're toning back the amount of mobility Valkyrie provides through Guardian Angel and reducing its duration to overall reduce the power of this ability."
Also in this update: a nerf for Junkrat! Just one, though.
Concussion Mine won't deal as much damage to targets that are farther away from the explosion's center, so "he can still dish out similar damage but he must now be more accurate with his tosses."
Mercy was my main during the early days of Overwatch, before Blizzard blessed her with Valkyrie, so I haven't really had to deal with the character's recent ups and downs. (Aside from competing against her, I mean. She tends to show up in a lot of matches!) That said, even if I prefer playing as Lúcio and Zen these days, it'll be nice to have Mercy in a stable place again. One day. Maybe.
"We will likely be iterating on these changes in the coming weeks," Blizzard says.
[ALL] Overwatch Patch Notes – January 30, 2018 [Blizzard]
via destructoid https://www.destructoid.com/blizzard-rolls-out-nerfs-for-mercy-and-junkrat-in-overwatch-485339.phtml