https://www.polygon.com/2018/9/1/17808826/rainbow-six-siege-operation-grim-sky-launch-date

Operation Grim Sky, The third season of Rainbow Six Siege, premieres on Sept. 4 for PlayStation 4, Windows PC and Xbox One. Ubisoft announced yesterday.

Players on the game’s test servers have been sampling Operation Grim Sky over the past two weeks. The new season brings in two new operators — Maverick, an attacker, and Clash, a defender. The Hereford Base map is also getting a makeover to balance it for competitive play.