https://www.gamespot.com/articles/new-rainbow-six-siege-update-out-on-pts-patch-note/1100-6462065/

Ubisoft has announced the test server for the PC version of Rainbow Six Siege is once again live. You can log into the test server to try out and provide feedback for several gameplay changes and bug fixes coming to Siege.

One of the more noteworthy changes is adding the option to enable or disable mouse scrolling inputs for weapon swapping. The mechanic has been in plenty of other competitive first-person shooters, and the PC Siege fanbase has been asking for Ubisoft to implement the feature since the game's release.