The Legacy Operations update for Battlefield 4 came out today. This new content is a separate download alongside an overall Holiday patch for the game. The content includes a 2015 update to Dragon Valley and Noshahr Canals. It also includes a Classic Rush game type and plenty of fixes.

The Holiday update, patch notes found here, is an automatic update for all platforms. The Legacy Operations is a separate download. If you're on PC, you can get the content by finding it under your game properties for Battlefield 4. It will be free. "Buy" it for $0 and then start the download.