Larian don't do DLCs typically but they've not ruled it out recently, an interview by digital trends with Swen at Pax West asked him about it and his response was
" We, as a team, peaked toward this release. So we’re gonna take a break. That actually is it. We’re tired. It’s been a long, long, long journey. It’s been six years of us only thinking about his game. So we need to refresh ourselves. And then we’ll see. "
Maybe they will, maybe they won't, time will tell, personally I believe they should DLC gets bad vibes because of horse armours and the crap EA/Activision Blizzard/Ubisoft have done over the years which has ultimately effected people's opinions about it, DLC/Expansions done right is beneficial to both the company and players, look at TW3 who honestly thought heart of stone and blood and wine were bad? Blood and Wine was longer than some games and for me it was worth every penny spent on it.
If they decide to do DLC/Expansions then I hope they can find a way to give Alfira as a companion, she definitely deserves to be one and that's a hill I'll gladly die on.