The point of no return in Dragon Age: The Veilguard is during the 'When plans align' quest where you have a meeting with Morrigan. While you're having the meeting with Morrigan the end of the game will trigger and you'll be given a choice.

The Veilguard turns a lot of common franchise elements on its head, but the way it keeps one franchise tradition alive is quite funny.

The Veilguard's best side quests arguably should have been a main story quest, due to what it reveals about the game's antagonist.