With the amount of changes that have taken place to Mercy (all nerfs) since her rework, it is clear that it was a failure.
Whether Blizzard will accept this, ignore this, or do what they did last time and claim it was still a success, is to be seen.
Many people have said it before, including high ranking Mercy players such as Animetic, that resurrect is what is keeping Mercy at a huge pickrate over the other healers.
(https://twitter.com/Animetic/status/1019736914029621248)
But no, Blizzard nerf her base healing instead.
No disrespect meant, but at this point, whoever decided that any of the Mercy changes were good needs to be shown the door.