Yes, the Usurpers and Outcasts IAP is extra content for the game. It wasn’t part of the original plan for the game, Kyle wrote most (all? I forget…) of the game then went back and wrote more content for Caitiff and Tremere playthroughs.
We’ll have more exciting news about this IAP on Thursday, so let’s all keep calm about Choice of Games having an IAP until then.
Also, we have a bunch of games that include IAP extras like this, if you aren’t aware. (All the Heroes Rise games, the Versus series, Pon Para and the Great Southern Labyrinth, Choice of Romance: Affairs of the Court, A Midsummer Night’s Choice, Choice of Zombies. And that’s just COG titles, not HG titles.)