That's the point. The only role CNN has is to read his twittering on-camera, then comment on it. They have to "report" on the President by reading his tweets, like anyone else can do.
Every time they read his tweets on the air, they demonstrate how useless and vestigial they are. This plays right into DJT's hands, and they know it, but they have no choice.
Vestigial ... beautiful word describing the media to start off my day...