https://www.gamespot.com/articles/rainbow-six-siege-update-makes-tons-of-changes-on-/1100-6458502/

Rainbow Six Siege is rolling out a whole bunch of additions and changes to the version of the game on its test server. Ubisoft announced it would be testing a new Pick and Ban system, along with implementing a series of tweaks, including ongoing changes to weapon recoil feedback and the addition of a bulletproof camera for some Operators. You can get a look at more details in Ubisoft's blog post. [Update: The test server update is now live and will run until Monday, April 30, at 7 AM PT / 10 AM ET / 3 PM BST.]

The developer is bringing in a new Pick and Ban system in this test update, which allows players to add Pick and Ban settings to custom games (meaning you can select certain operators to allow or remove from play). Ubisoft is looking to test the UI and player experience of the Pick and Ban system in the game, to get a sense of how it fits into Siege. The developer is also continuing to work on the weapon recoil system and continues to tweak it in this phase.