Yeah, that's probably a release date -- it would be an awfully long wait for another trailer! If this holds, Journey of the Brave would be just shy of two years in production: quite a bit longer than the sixteen months it took for LBT 12 to be produced (while the TV show was being produced simultaneously). Certainly looks like they're working hard on it and from what we've seen so far, it looks like it's paying off!
For comparison, in the two and a half months between Curious George's trailer release and its film release, there was a song trailer and at least one normal trailer, as well as ten movie clips released about two weeks before the release date.
Also, so far it looks like there's at least two Barbie trailers out (one posted in February, the other posted in June) and one Thomas trailer (though that was posted in April by another user before Universal posted it in June); both of them will be released on September 8. So it seems like they've been having fairly long promo campaigns too.
Universal seems to put the trailers on its channel closer to the release date however, apart from one movie released on Blu-Ray on January 6, the latest movie they have a trailer on their channel for will be released on October 6. So perhaps they'll start uploading November-December or so? Guess we'll find out soon enough.
