All trailers will be properly labeled so fans know what they're seeing.
Art promoting the Xbox Games Showcase and Starfield Direct for June 11 at 1PM (ET).

The head of Xbox marketing Aaron Greenberg said on Twitter that there will be no full CG trailers shown off during the upcoming Xbox Games Showcase. Greenberg states that none of the first-party games in the show are full CG trailers and that everything will be either in-game footage, in-engine footage, or a blend of in-game footage with some cinematics.

He continues on to say that each trailer will be labelled to indicate what the footage is showing so that it's clear to the fans watching at home. There will also be no trailers for movies or TV shows shown during their stream.

Related, Greenberg says that this Xbox Games Showcase will not feature only titles that are supposed to come out within the next 12 months. If you recall, last year's Xbox Games Showcase featured titles that Microsoft said would be available within 12 months. Not every game in that showcase made it out within that 12 month window. The most notable game to miss that window being Hollow Knight: Silksong, which still has no release date set.

The Xbox Games Showcase begins June 11 at 1PM (ET) with a Starfield Direct beginning right after.