The developer is currently selling a Season Pass for Uncharted 4: A Thief's End which promises single player DLC for the game after launch. Speaking to Gamespot, director of communications at the studio Arne Meyer said that they don't quite know what that content is going to be yet though.
I was talking with Neil [Druckmann, game director] about a month ago when that was just revealed and reading all the stories and fan reactions about it. It was interesting because people are thinking maybe we'll hold back some of the story or stuff like that. But he's like, 'I have no idea what we're going to do with that.'
We're so busy on the actual game and I was talking to him and saying that we're taking a big risk here because we have no idea what we're going to do yet. We've committed to putting something together and it has to be a high level of quality and have a really engaging story, and we've said that this is the final chapter. We have all these things we need to resolve at some point but we have no idea what that is.
While Naughty Dog make very good content, and you can usually bank on that, it does seem weird to buy DLC that even the developers have no idea of the content of. That's on each buyer I suppose though.