Since the DLC is going to be very pirate-y (presumably), it would be a great opportunity to bring back naval combat. If so I foresee it being done in the ToB style, as in no dedicated navies, armies become fleets of warships when seaborne instead. This would also mean changing the battlemaps of coastal towns to include the sea and landing spots. All races would probably only get 1-3 different ship types for their rosters since unlike the previous TW titles with naval combat, you can't reuse any naval assets and have to make unique ship types for every race.
I think that would actually justify the waiting period and this coming before the SKV/LM LP.