I have a feeling we're in for a game with a darker color scheme again, teasers are always made to give the audience a fitting first impression, and the two colors that really stick out to everyone atm are black and orange (or red, depends on who you ask), so I think those will be the key colors in the game's visual design. In that case the more playful menu design of Brawl/Smash 4 wouldn't fit the serious feel that the color combination gives off, I'm not sure if they'd go back to a more traditional menu, but I'm not expecting the same kind of menu again that we've gotten in the past two installments.