Rough Translation from KHInsider of the Full Eraqus-Xehanort conversation in the new KH3 Trailer:
New lines of dialogue are in bold
Xehanort: Have you heard of the Ancient Keyblade War?
Eraqus: Of course I do.
Xehanort: That thing where long, long ago, Keyblade Wielders struggled over the light
Eraqus: Yeah, the Master's favorite story.
Xehanort: I guess they wanted to use the light they'd struggled for to make Kingdom Hearts appear, and do something
Eraqus: Guess so… I can't understand the reason why anyone'd start a war
Xehanort: So, you know of the Lost Masters
Eraqus: What's that?
Xehanort: They're the ones who started the Keyblade War.
Eraqus: Never heard of them.
Xehanort: No, more like, it was for their sake… I think.
Eraqus: What are you even talking about?
Xehanort: You can drop the facade.
Eraqus: Know what?
Xehanort: On that land shall darkness prevail and light expire. You'll soon be up for masterhood candidacy, there's no way you don't know.
Eraqus: Well.
Xehanort: The staring eyes see all. The future, it's already been written.
Eraqus: Who's to say I can't change it, and maybe Light will prevail.
Xehanort: You're rather confident. But aren't you at a disadvantage in this match?
Eraqus: But unlike Darkness, there is more to Light that meets the eye. You might be surprised.
Xehanort: Oh, I hope so.