The Shadowlands Sanctum of Domination raid opens July 6th on Normal and Heroic difficulties.
Here's the remaining schedule:
July 13 – Raid Finder Wing 1 and Mythic Difficulties
July 27 – Raid Finder Wing 2
August 10 – Raid Finder Wing 3
August 24 – Raid Finder Wing 4
Note that the minimum item level for Raid Finder is 195.
Currently the gear drops are shown to be RF 213-220, Normal 226-233, Heroic 239-246, and Mythic 252-259. Like Castle Nathria, only the last two bosses drop the higher-level gear.
See the Wowhead overview
which shows the location, and a raid guide
Here are some videos: