A press release announcing the content this week did not mention Wii U whatsoever.
No explanation regarding why the Wii U is being passed over was provided. DLC for Assassin's Creed III was available on Wii U.
The main chunk of Assassin's Creed IV: Black Flag DLC revolves around the nine-mission single-player storyline Freedom Cry. This is set fifteen years after the events of the main campaign, and casts players as Edward Kenway's first mate Adewale, who's now a fully trained assassin, but finds himself shipwrecked in Saint-Domingue with no crew or weapons.
A season pass will also provide the Kraken Ship Pack, which gives owners more customization options for Kenway's Jackdaw ship. This will not be available to purchase separately, Ubisoft said.
Ubisoft also said additional DLC will provide players with more single-player missions, weapons, skins, and collectibles, alongside new characters for the game's multiplayer modes.
All of Assassin's Creed IV: Black Flag's DLC will be released before March 2014.
Assassin's Creed IV: Black Flag launches on October 29 for Xbox 360, PlayStation 3, and Wii U. Xbox One, PlayStation 4, and PC versions will follow in November.