I've always felt that way about prerelease stuff. Give me a title, a release date, and in the rare cases it's not a remake/sequel, a hook. I don't need endless hype.
That 5 second clip is the ad and then it plays the rest of the trailer which is also the ad. They know post people will skip the ad so they have a short spot at the beginning as an attention grabber in hopes you won't skip.