The Call of Duty: Modern Warfare 3 reveal is officially scheduled to take place in Warzone on August 17.
Yes, the existence of Modern Warfare 3 was already confirmed on August 7, but this is the Modern Warfare 3 reveal, which will presumably be tied with some sort of actual information about the game itself. So far, the only concrete things we've gotten have been a very brief teaser and a countdown to another trailer set to reveal Makarov.
The devs offered a few details on this Warzone event back when it was announced as part of the Season 5 rollout, saying "Drop into Call of Duty: Warzone to experience the worldwide reveal for Call of Duty 2023 in a limited-time event. Join the ranks of Shadow Company to take on Konni forces and secure the chemical weapon threat before it’s too late."
Activision announced the August 17 date for the Modern Warfare 3 reveal with a tweet encouraging fans to sign up for text message 'intel' alerts. The same phone number was buried in yesterday's teaser trailer, and right now it's responding to texts with a map pointing to various missile locations on the Warzone map. It looks like we can expect some sort of ARG in the days leading up to the event.
As with pretty much everything related to Modern Warfare 3 so far, the August 17 date leaked ahead of the official announcement, and it's likely those sorts of leaks are going to continue leading up to the game's launch on November 10.
With or without official info, there's some skepticism about how substantial a sequel Modern Warfare 3 will actually turn out to be.