It's happened twice now.

"Why would they nerf the first Coil?"

And then they nerf it.

"Why would they nerf the second Coil?"

And then they nerf it.

Why do they nerf it? Because it's in the DF, for the general populace, they expect you to be able to clear it with random strangers who may or may not know the fight in the time allotted. That is not happening in it's current state, so it's going to be nerfed.

Again, this has happened for the last 2 Coils, I don't know why people think the last one suddenly won't get nerfed, especially if you're expecting the Echo to be added to begin with.