Access to Call of Duty: Warzone continues as normal until November 16, when a short “intermission” takes place during the launch window of Warzone 2.0:

• At approximately 8 AM PT on November 16, Call of Duty: Warzone servers will temporarily go offline as Call of Duty: Vanguard Season Five concludes.
• At approximately 10 AM PT, Call of Duty: Warzone 2.0 will be released as part of Modern Warfare II Season 01.
• Once the Warzone 2.0 ecosystem is fully stable, and after a small development break for Thanksgiving for the developers who observe this U.S. holiday, Warzone is planned to be relaunched as Call of Duty: Warzone Caldera as a separate experience. This will happen at approximately 10 AM PT on November 28.
• As a token of our appreciation, those who played Call of Duty: Warzone will be gifted a few items to use in Warzone 2.0.

Check out the Warzone 2.0 Season 01 overview blog for full details.