...a new game board with large islands on which ground attacks can be carried out
That sounds to me like a new approach to one of the core mechanics, rather than just adding a board for six players...
I noticed this too. I didn't think they would be that risqué. Maybe they do have something special up their sleeves.
Maybe there is an additional "battle board" where players can actually maneuver troops. Thus there will be tactical decisions to make.