The Black Panther trailer follows the same model as the recent Star Wars: The Last Jedi trailer and an increasing number of big-budget movie trailers: a collection of disconnected (yet appropriately “cool”) scenes that catch the attention and open space for all kinds of speculative discussion in fandom, but provide very little concrete information beyond that. Characters aren’t named in the trailer, nor are their relationships or allegiances defined. Outside of the fact that the movie looks good, there’s not a lot the trailer actually tells anyone about the finished product.
There are pluses and minuses to this approach, with the obvious positive being that such trailers avoid the risk of accidentally spoiling the movie by revealing too much ahead of time. Black Panther, along with Star Wars: The Last Jedi, both have the added benefit of the fact that the audience is already excited about the project. There’s no need to explain anything to the audience, or even try to sell the film at all, because they’re already onboard.
Other movies don’t have that same chance. You can look at the trailers for Valerian or, better yet, Blade Runner 2049 as following a similar low-information model for trailers — although, instead of going for the overwhelming, over-the-top quick-cut spectacle of Black Panther and The Last Jedi, Blade Runner 2049 was more along the lines of slow-moving tone poetry — but, without the benefit of a contemporary successful franchise behind it, audiences had no idea what it was looking at, leaving them disinterested in the movies themselves. (Blade Runner 2049, despite positive reviews, has underwhelmed at the box office.)