Fixing the game does not equal adding new content lol. Once there is little to no bugs they have no reason to waste more of their resources on a game thats already massive success, the obvious move is to move on to the new project just like Sven already did
No studio operates like this. Imagine if CDPR just took their Witcher money and didn't release any DLCs or Capcom didn't release expansions for Monster Hunter. When you have something good going, you keep it going. Swen himself said they weren't done with BG3. He wasn't talking about bug fixes.
You didn't answer a single one of my questions. Why bring back VAs for epilogues that no one apparently needs? They just need to fix the Minthara bugs, so why bring the VA back for any new lines? Why would Swen say they'll consider DLCs? He could've just said no.
The reality is that Larian isn't done with BG3, and they'll almost certainly release a definitive edition. That entails a bunch of new content to sell to a new player base.