If it was just a workprint or something, would all the credits be correct yet?
Since we're talking about the first teaser poster, I doubt there would be any credits at all on the real one. The early teaser posters for the 2009 movie didn't have credits, just the release date, the website address, and the corporate indicia. This site
has them in chronological release order, and there were fifteen
teaser posters released before we got one with credits on it.
So at this early stage, any poster you see that has credits at all is probably a mashup by a fan who's getting ahead of the curve.