Katarina Ulti Ninja Nerf is Bad Manners
When an entire champion is designed around an unreliable ulti with Grievous Wounds on it, acknowledge the nerf in the patch notes and give us some context.
A strong GW on Death Lotus is integral to her entire design and counterplay. You count CCs, interrupts, and displacements, pick a target in guaranteed kill range before they escape, and execute a combo. If you do that, your reward is a kill and a way out of the fight. If you get anything wrong, you die.
The new GW is going to be the margin on a kill at crucial points in the game. Missing a kill often means feeding a kill. It's a pretty big tilt to a kit that's intentionally balanced on a razor edge. There's not a ton of ally healing in the game, but it's most common and most impactful at the points that are most crucial or difficult for Kat to execute.
Kat roams bot to get fed since her early laning and farm ranges from disadvantage to total shit. Every bot lane takes Heal, and nearly all allied healing in the game is in bot lane. When laning is balanced around getting the roaming kills at 6, this is a kick in the nuts. In team fights later on, you have a LOT more to watch for, and the margin for error is very high. I've been in many games where GW decided the outcome after a Kindred ulti heal, Fiora heal, or Janna heal (after knockback during channel on low targets).
This is in addition to GW being nerfed by 10% for personal healing in the brave new world of "FREE HEALING FOR EVERYBODY!" AD items/masteries. It's a really shitty nerf at a really inopportune time compounded by other indirect nerfs and disrespect I've mentioned about other changes.
So please, just have the decency to mention that you considered the impact to the two champs who got a nerf to their kit via GW. Maybe mention that you have adjustments in mind and you'll keep an eye on it. BM Rito.