User blog comment:Wiggles The Pootbird/RWBY Volume 4 update?/@comment-5430952-20160919174532

All that's been said from RT is that the trailer is "Coming Soon," and now that they've finished all the animation in RWBY Chibi, they can focus on other projects, like the trailer perhaps.

Other than that, we're bound to get the trailer, or maybe V4E1, at the Tugg screening of V3, which I'm attending. Definitely go if there's one near you, it's going to be a blast. :D