User blog comment:Battlefield4us/RWBY shows up at RTX after all! and Fanart found in new RT short/@comment-5717877-20150722045151

While there is gonna be a RWBY panel, Vol 3 will not have a premiere. There is a possibility they could show off a trailer or the opening animation (the latter is more likely to come first).

If I were to estimate when the first episode will premiere, I'd say around the time New York Comic Con rolls around. We got confirmation that Vol 3 is expected for a late fall/early winter release, so that doesn't sound too far fetched