His handlers can’t script a phone call and we must assume he is incapable of a cogent conversation. He probably couldn’t keep track of who he’s talking to. With Kamala in the wings, they don’t dare pull his plug. We are in serious trouble.
Rich Little might be imitating him and reading his script. Or some other professional mimic. It’s a phone call, after all. And if there’s video, they just need a doppelganger who can move his lips convincingly while the mimic reads the script.