So I was discussing this with a couple of friend before and with how the maps are being added and developed, especially in normandy, we said it would be awesome for the game to progress based on the outcome of the battles.
Guessing it would be quite a lot of work but for example starting with the D-Day map on the beach landing there. If allies win it progresses in-land, if they fail they try the landing at Ver-sur-Mer. Then if the Allies capture Le Bre for example but fail to win the next map, the Axis attack Le Bre with Allies defending it to try and keep the progress.
With many of the maps looking like they are connected/following on from previous maps, this could really work I feel across all of the campaigns.