Yeah, it’s great that 20th Century Fox is all about the high-quality but they’re still just trailers. There’s nothing particularly innovative about this, it’s like ordering a double-hamburger instead of a single. It’s the same basic thing, just more of it.
The fact that the trailers are downloadable is interesting in that it means people could potentially download it and host it on third-party server for others to view. This means less visitor traffic for the studios’ sites which may be why the author of the article mentions advertising as a potential income source.