As PCGamesN reports, lead gameplay designer for Battlefield 1 Alex Sulman wrote on the forums that as a part of “Fire & Ice” update “Operation Campaigns will be open to all players, always, regardless of the Operations contained. Yes, that means if you have only the base version of Battlefield 1 you will still be able to play Operations that are part of expansions you do not own”.
The post then goes on to note that certain maps, elites, vehicles, and weapons are only available in the campaigns that change every two weeks according to the rotation.
Our goal here is to ensure the best chance at the most populated servers we can. We feel opening up the content to all players is the best way to do this.