The Veilguard director Corrine Busche has assured fans that the upcoming sequel won't have any DLC like that and that it will be "complete out-of-the-box package".
Busche explained how she's a big fan of the Trespasser expansion, but also noted that it was "so essential to the Dragon Age: Inquisition story, it arguably should have been part of the base game."
In turn, this became a critique that BioWare took to heart, and wanted to avoid with The Veilguard. "We really wanted to make it the most complete out-of-the-box package we possibly could, from a player experience, the narrative, and everything else. That's entirely our focus right now."
That isn't to say there won't be any kind of DLC, as Busche did say it's "hard to say what the future hold, but I will say that we had discussions about 'should this game end after Act One?' And the answer was an emphatic no - we needed to tell the whole story of The Veilguard."
Further than that, she also note that the series has a "rich tapestry of lore and concepts and people and places" that could be great for a DLC, "so never say never."