nerfing her Ult is a bad idea because it's a long cooldown (regardless she builds CDR).
It's like Riot punishes her for building CDR. Or you try to find something reason for her CD nerf.
Like "oh who cares if her CD increased by 30s, if by maxing CDR it's the same lategame".
In both cases, I'm against it. That is heavy nerf blow to so called diversity.
We already have few examples of Riot going into stupid mode with messing with similar cases.
Lisandra having her mana regen halved cause of weak-as-fk passive
Sion has less starting HP cause of his passive shield
Sejuani + cinderhulk. She was tad too strong, but nowhere near to be thrown into full gutting guillotine
Teemo + Liandry causing his mushroom getting heavy nerf to ratio..
Riven has low hp regen because of her shield. Obviously everyone builds hydra on her.
Le Sin having... Well.. he has no drawbacks lucky fker.