Six classic maps are returning in Battlefield 2042 as part of a tool for making your own game modes. The maps include Caspian Border from Battlefield 3 and Arica Harbour from Bad Company 2. The mode-editing tool is called Battlefield Portal and it works in a web browser, letting players create shareable game modes on a selection of old and new maps. You could make a mode that allows only repair tools, for example, or pits teams from distinct eras of warfare against one another.
In other words, you might force a bunch of World War 2 Germans armed with knives to fight squads of US soldiers from Battlefield 3 armed with modern LMGs. The important thing is they can duke it out in a fancy new version of El Alamein from Battlefield 1942.