Yeah, I was about to say, "but trailers aren't rated!" Good thing I clicked on to the next page before posting! Actually, my understanding is that we only have 2 types of trailers in the US- green band and red band. The vast, vast majority of trailers are green band- the ones that say "General Audiences." This is so that even if the film is rated R, the trailer itself can be put in front of a movie of any rating (though obviously, they probably won't put a trailer for an R rated movie in front of a kid's G-rated film
Red band trailers contain restricted material, but they aren't that common; 21 Jump Street had one because they wanted to show some of the raunch, and sometimes horror films have them, but I don't think they bother in most cases.
I am ASSUMING that the film itself won't be rated PG
In fact, have we gotten a definite rating yet? I think that the consensus has been that it will be PG-13, though I have hoped for an R. ETA- according to Box Office Mojo, it's "not yet rated." But I seem to recall Zanuck or someone remarking that it was aiming for PG-13. Did I imagine that?