We’re in the process of correcting this and you should see the update in the article “soon”. World difficulty is available (it’s in the drop down options) on August 11 and all other difficulties are available on August 18.
Week of August 11
- Lair: The Tidebound Grotto - World Difficulty
Week of August 18
- Lair: The Tidebound Grotto - Normal, Heroic and Mythic (Flexible-Scaling) Difficulties