https://www.gamespot.com/articles/overwatch-christmas-update-adds-new-skins-mode-as-/1100-6455589/

Blizzard has kicked off Overwatch's celebration of the holidays, bringing back the Winter Wonderland event from last year. This isn't a complete retread, however; while you're again able to access what was available last year, there are also new skins and a limited-time mode to check out, among other things.