We finally have the release date for Shadowlands, as Blizzard has announced how long the delay will be. We have just under a month to wait with the next expansion's release date on November 23rd (or the 24th in Europe/Asia).
We also found out that the first raid will not be delayed, but will launch alongside the Mythic+ and PvP Season 1 on December 8th. We also got a separate blue post detailing the full raid unlock schedule:
In just a few weeks after the release of Shadowlands, Season 1 will begin and the gates of Castle Nathria will open as the expansion’s first raid experience.
Infiltrate the iron-barred walls of Castle Nathria, a 10-boss raid located in the shadowy realm of Revendreth. Face off against unfathomable horrors in a race to uncover a sinister plot and save these lands from a dark and twisted future.
Raid Unlock Schedule (North America):
December 8 – Normal and Heroic difficulties
December 15 – Mythic Castle Nathria, Raid Finder Wing 1
January 5 – Raid Finder Wing 2
January 19 – Raid Finder Wing 3
February 2 – Raid Finder Wing 4
Shadowlands Season 1
Once the gates of Castle Nathria open on December 8, Shadowlands Season 1 will also begin which introduces a new seasonal affix in Mythic Keystone dungeons along with a new season of PvP action.
And here's the Shadowlands release and pre-expansion event release dates (November 23rd and 10th):
Greetings heroes of the Horde and the Alliance,
On behalf of the entire World of Warcraft team, I’d like to extend a heartfelt thank-you for your patience as we’ve continued to work on Shadowlands, and for all of the words of support after we made the tough decision to delay the game. Today, I’m happy to share that the expansion will be arriving November 23 at 3 p.m. PST (November 24 at 12 a.m. CET).
We’d like to thank everyone across the WoW community who helped us get where we are today, including players leveling up new characters in the Shadowlands pre-patch (and keeping Azeroth’s barbers extra busy), as well as all the beta testers who continue to provide us with invaluable feedback on the expansion.
Since we first told you about our decision to delay, we’ve used the time to further polish the expansion and shore up the endgame, including overhauling the combat and rewards in the Maw, and reworking the Covenant systems to make your choice more immediately impactful and have clearer long-term goals. Now the team is in a great position to get things the rest of the way to the finish line before November 23—and as always, we’re committed to working with you to improve the game for as long as you’re out there playing it.
Now that we have our launch date, we’re also excited to tell you that our pre-launch event will kick off November 10, so steel yourselves to take on a flood of the Scourge. In addition, we’ve set a December 8 date for the opening of our first raid, Castle Nathria—which takes players into the heart of Sire Denathrius’ lair in Revendreth—along with the start of Shadowlands Season 1.
We’re looking forward to seeing everyone take their first steps into the Shadowlands and forging their destinies—but in the meantime, we’d like to show you just a little bit of what’s waiting for you beyond the veil.
See you on the other side,
-John Hight, Executive Producer of World of Warcraft