Maybe they want to hold their cards close to their chest. But even Alien had promo material back in the day. Not sure if they ever mentioned the creature though, prior to the movie's release. Here, though, it's not much of a surprise, unless Scott tweaks or fiddles with the traditional alien forms. It wasn't a surprise in Aliens, either, with the exception of the queen. I'm feeling a similar feeling here. I know what's coming but it's going to be bigger. Shotguns, aliens (plural), dark-and-unrelenting. Express elevator to hell, goin' down (again)!