Imo they didn't just allow other players more room for counterplay but also nerfed Zed's potential to counterplay which was what Zed was all about.
The W slow was just overkill and I think the ult nerf wasn't that neccesary.
Increasing the ult CD and maybe the W slow wouldve been good. But this is overkill.
Zed will still be strong, but almost certainly won't be as faceroll as before. His waveclear and pushing ability remain, he will probably just have more trouble 100->0ing a squishy than he did before, which is probably for the best.