https://www.gamespot.com/articles/rainbow-six-siege-outbreak-and-chimera-update-ever/1100-6456699/

Year 3 of Rainbow Six Siege is set to kick off soon with the launch of the Chimera update. While it will bring some of the features we're accustomed to seeing with each new season of content, like new Operators and maps, this one will be even bigger than usual, due to the Outbreak event.