From a new interview: "We used our artifacts to drain the corruption from the sword in 2018. Everything is fine. It's just a big splinter."
Okay so why was Azeroth crying out, why were we healing the world, and ultimately, where did that plot even end? We never healed Azeroth, we just killed N'Zoth, who was only released BECAUSE of all of the Azerite we gathered in the first place!