As seen in this video on the official Call of Duty channel, the beta dates have been announced for Modern Warfare 4.
The early access will start on all platforms (except for Nintendo Switch 2) the 21st of August up to the 25th, and the open beta (including the Switch 2) will be from the 28th of August till the 1st of September.
You can find the Beta FAQ at the following url : https://www.callofduty.com/modernwarfare4/beta
