Paid customers get access to Act 5, the final act of the game.
I doubt it there probably will be act 6 because in act 5 rhyll and eburon will argue who's will rule lowlands then you only can choose one of them if we choose rhyll eburon will back to wilderness and if you choose eburon rhyll will betray you and run away
Eburon maybe will not do anything, but rhyll probably streak you with another nation/realm army