Pretty much everybody agrees that we don't want to see John Branca as the narrator, and personally I would prefer if there was no narrator at all. However, if they do decide to add a narrator, I feel like the only character who could bring something insightful to the story would be Joe Jackson.
First of all, his controversial character is more interesting than Branca's serious lawyer tone could ever be. But mostly, no relationship Michael ever had had more impact on him than his failed relationship with his father. It was Joe and his dream that started it all and set Michael on the path to become a superstar. Unlike Branca, Joe was there from the beginning until the end. Unlike Branca, Michael could never completely cut him out of his life, because he was his father and Joe refused to let Michael push him out of his life, even breaking into his house when Michael refused to see him. Even when he was not present to witness certain events, you could see him always keeping up with what was going on in Michael's life, even from a distance, and always wanting to be involved.
Having Joe as the narrator would also be an interesting way to show the contrast between how Joe acted in private vs in public, how he mistreated Michael, destroyed his self-esteem and never showed him love in private, whereas in public he always defended him and spoke of him with love and pride.
I mean, this is what Joe was telling Michael in private, and it could be shown in a scene:
“God, your nose is big. You didn't get it from me! Your nose is so big and it’s so ugly. Look at it. Oh, it’s disgusting, I can’t look at you. Turn away from me.”
And this is what Joe was saying in interviews, and they could have Joe say it as the narrator:
“That boy's so sensitive about his nose. Do you see anything wrong with his nose? Me neither. Threatened to have it fixed. What can he do with it? I told him I'd break his face if he ever had it fixed. He's got a great nose. It looks like mine.”
Even when Michael tried to keep Joe away, he was still ever present on his mind, influencing how he felt and the things he did. When Michael told this to Karen Faye after the bridge accident: “The only thing that I heard in my head, was my father's voice saying to me, MICHAEL, DON'T DISAPPOINT THE AUDIENCE!”
Or when people wonder why he didn't just cancel the This Is It shows instead of pushing himself beyond what his body could endure, the first thing that comes to my mind is this story Joe told:
“After the ambulance got to the show and worked on me, I was barely able to get up. I remember Michael and the boys looking at me with their youthful eyes, full of confusion as if asking “What do we do now?”. I looked straight at them and without any hesitation said “You go on stage and do the show, like nothing has happened. The show must always go on!” Michael internalized that lesson and over the years, even in pain, stress, sadness, he would never let the public see it. He was a professional till the end. In my eyes “The Greatest Entertainer that ever lived”.
As a narrator, Joe can explain so much of the stuff that happened in Michael's life. He's the one who taught Michael he had to go on stage no matter the pain and sadness.
