Blizzard has revealed Patch 12.2, titled Midnight: Eclipse, and it's putting Xal'atath's endgame front and center.
The reveal cinematic frames Xal'atath as having stayed a step ahead of Azeroth's heroes at every turn so far, and Eclipse is being pitched as the patch where that finally gets addressed head-on - players moving to confront her directly instead of just reacting to whatever she's already set in motion.
Alongside the patch reveal itself, Blizzard used the same WoW: What's Next panel to tease two things outside the story: a follow-up to the Mists of Pandaria Remix event sometime next year (no name attached yet, just confirmation it's still coming), and a brand new standalone WoW game mode that's being detailed in a separate reveal later the same day.
Beyond the cinematic and those panel comments, nothing else about Midnight: Eclipse has been shared yet - a proper look at what the patch actually adds should follow once Blizzard is ready to go into specifics.