Since the film is supposed to be about the new Jedi order, it’s concerning that John Boyega hasn’t been announced to be returning, as well. I think he’s previously said that he’s done with Star Wars, but hopefully enough of that Disney money would bring him back.
I realize the Lego Holiday Special and the like aren’t necessarily canon, but I think it would be awesome to see Finn as Rey’s Jedi apprentice just like in those shorts. I’m not sure that a film with just Rey being the only Jedi would be all that interesting. I guess we could see “new” characters such as a grown up version of broom boy since it’s 15 years later. Grogu might be there, too.