IIRC Larian devs at some point have mentioned that they are fundamentally opposed to the idea of paid DLC now. To the level that a lot of Larian fans would believe the presence of such a thing in BG3 to be a betrayal at first glance, though I also believe in terms of actual practicality that most people will end up justifying it in their minds and come to terms with it within the week.
I think the last game they made that had that was with Divinity 2 (the main series Divinity, not Original Sin), which was well over a decade ago. However, as this is a WotC-contracted game, it's possible that BG3 may end up with paid DLC down the road.
Technically, Divinity Original Sin 2 had a singular Paid DLC, but everything was upfront about it and it was super cheap, and most people ended up getting it for free I think.
But yeah, them immediately going to small DLC packs or such would definitely feel like a complete betrayal. That and the company Electronic Arts has completely soured me to DLC companions. In particular, Mass Effect 3 is when I first realized that when I bought a DLC for a companion I was getting ripped off most of the time. That game had the audacity to do on disk DLC where the only difference between having the character (Who was super important to the overall story btw, like some of the biggest revelations of the series) was changing a statement from 0 to 1... And then I looked at other games and found that often times the character was either something cut off from the main product, or made alone to squeeze more money out of the game. DLC wise, I vastly prefer full expansions or standalone experiences. But even with Larian I think I would be pretty soured.
For Larian to properly sell a DLC to me, I think it'd have to be a full on expansion like the Witcher 3 expansions or a new Module like adpating existing DND modules into a videogame format. New classes, subclasses, and companions I would HATE to see behind a paywall, if added later on as grabbags that is fine. But if I see "DLC Pack #1: Xanathar's Guide To Everything," I do not think I will be particularly happy.
