Apple appears to have debuted the new channel, which was noticed this morning by MacStories, about a month ago. The channel seems to have launched when Apple announced plans for a revamped Apple TV app and a new Apple TV+ streaming service.
Quite a few videos have been uploaded, many of which are clearly labeled with titles like "Official Trailer," Interview," or "Clip."
Trailers for many popular upcoming movies are included, such as "The Lion King," "The Secret Life Of Pets 2," and "The Joker," along with clips and interviews from "Game of Thrones," "Veep," and more.
The channel features trailers for Carpool Karaoke: The Series, which suggests this is where Apple will share trailers for its original TV shows and movies as the Apple TV+ service's fall launch approaches.
Apple's updated TV app is already available to developers and public beta testers who have installed iOS 12.3 and tvOS 12.3, and it will be available to everyone when those operating system updates launch.
It appears that the Apple TV channel will be used in conjunction with the revamped TV app to promote television content that's available to watch through the TV app.