He put on a showcase for Seth McFarlane. It's like those SNL Guest Monologues where the guest wants to sing and dance, to demonstrate he can. Except in that context, it's not so objectionable, ad the monologue is supposed to be about the guest.
What did the various song and dance routines have to do with the movies under consideration? High Hopes had nothing to do with them at all. No lyrics were even altered.
Ironically, Seth McFarlane now insists upon himself.