And, as been said, if there’s good mod support, additional multiplayer modules, plus ongoing enhancement of the game through DLC and expansions, it has the potential to keep selling solidly for some time after release.
In an AMA in 2020 Sven indicated that there are currently no plans for "major DLC" as it seems like something Larian isn't interested in much in general. DLC I could see in the form of something like D:OS2 got with 'gift bags'. I could also see a handful of random smaller side quests being added as well - kind of like D:OS2 got.
But it seems unlikely that Larian develops a whole new campaign or a major expansion for the game. Though maybe if sales and demand are high enough they change their mind on that.
