I really dislike Smash's approach to trailers, but I don't really think having trailers alone is a bad thing... I'd prefer to only give certain characters trailers - like, Waluigi gets a trailer but Colgate is shadow-announced on Twitter for example - and have trailers for certain pieces of non-character content with the same production values as the character trailers. A trailer for the Bowser's Castle stage or wavedashing would go hard.