Soraka is the ultimate healing champion in League of Legends, with Grievous Wounds being her main counter. Anyone can see why her ultimate removing that is an issue.
PAtch 12.12 has come and gone, and it leaves balancing changes to the durability update in its wake. One of the indirect, buffs the durability update did was buff hearing, even while nerfing it a bit. While this seems like an oxymoron, we assure you it is not.
After all, healing restores health at a static number, and with that health now hidden behind more layers of armor, it remains more valuable.
However, it wasn't always the case. In patch 11.18, while Grievous Wounds had a 60% anti-healing effect, Riot Games buffed SOraka's ultimate to remove the effects of GW.
Nowadays, the GW effect is not nearly as strong, while the meta is geared towards champions like Soraka heavily. To combat this, Riot Games have reverted the changes to her ultimate in patch 12.12, making it not remove GW anymore.
Her scaling remains the same, however, and healing is running rampant in the game, so we don't see how just one nerf to healing, on a single champion, will be enough to restrain the healing meta.
However, it is definitely a start. Now, if only there was a way for assassins to be able to kill her with the durability update in place, that would be perfect.