With Patch 1.2.3, the Abattoir of Zir, a new seasonal endgame system, will be added to Diablo 4. In a video shared by Blizzard, details have been revealed regarding how the Abattoir of Zir will work exactly – and it looks a lot like Diablo 3 Greater Rifts!
Abattoir of Zir Seasonal Event Revealed BlizzCon Diablo 4 Campfire Chat Summary
As shown in the screenshot below, players will have 10 minutes to kill enough monsters to spawn and defeat the boss – just like Greater Rifts in Diablo 3.