Call of Duty Vanguard. The newest WW2-based entry to the series will be revealed tomorrow (August 19th) within Call of Duty Warzone. The event is called #BattleofVerdansk and will happen at 10:30 am PT according to the official Call of Duty Twitter.
There also appears to be some sort of loot drop that will feature blueprints, a skin, a timepiece, and more! This event is also featured with Double XP, Double Weapon XP, and Double Battle Pass XP and sounds to be some sort of battle against an armored vehicle.