Potentially the Arbiter narrating her judgement against Uther, Kael’thas, Draka and Cenarius.
edit: I don’t think they’re going to narrate Thrall, Baine, Anduin and Jania.
Thrall, Baine, Anduin and Jania Spoilers
https://wow.zamimg.com/uploads/screenshots/normal/955149.jpg?maxWidth=300
https://wow.zamimg.com/uploads/screenshots/normal/955148.jpg?maxWidth=300
