Ahri nerfs are in the wrong direction.
I'm not an Ahri main, but I'm pretty sure the reason everyone hates playing against this piece of shit is because of the 2 second charm that also enables a 20% damage increase. Ahri's E has become much like Zoe's E, where getting hit by it almost guarantees you getting one shot. Nerfing her ultimate cooldown will only push her back into obscurity, without actually solving the real issue.
This problem isn't exclusive to just Ahri, numerous champions were nerfed due to having ridiculous CC abilities (Nocturne E Fear, Zoe E Bubble), and instead of having their durations or bonus utility reduced, they nerfed every other part of their kit without removing what made those champions so frustrating to play against in the first place.