Larian Studios Won't Make Baldur's Gate 3 DLC, Expansions, or Baldur's Gate 4 - IGN
www.ign.com
At a Game Developers Conference (GDC) panel today, Larian Studios founder Swen Vincke dropped something of a bombshell by revealing that the developer isn't planning to release any expansions or DLC for Baldur's Gate 3, nor a Baldur's Gate 4.

tweet update:

Also - we’re not done with updating Bg3. There’s still a bunch of stuff coming like mod support and extra cinematics for some of the endings. Just not new content.