https://www.gamespot.com/articles/rainbow-six-siege-outbreak-and-chimera-out-now-on-/1100-6457186/

The latest free expansion for Rainbow Six Siege, Operation Chimera, launches today, thereby kicking off Year 3 for the popular shooter. This is a more substantial update than usual, as it adds new content to not only the core, competitive multiplayer component of the game, but it also introduces a new co-op event mode for a limited time. After a period of server downtime, Operation Chimera is now live on PC, PS4, and Xbox One.