On a side note, I dont think they will make either Mario or Luigi talk, outside of their one liners that already exist on the games.Rather, I think they will go the Bowser inside story route.In which a new charachter, like Starlow, is there to act like the team representative, as the one who talks with others.It could work
My (locked) thread about how difficulty should be a decision for the developers, not the gamers.
https://gamrconnect.vgchartz.com/thread.php?id=241866&page=1