RPG_Fanatic
Member
VA in and of itself is usually done later into development in most games, so I can imagine she was brought in to purely read for that trailer, and will be called back once the roster has been fully designed.
As far as getting any official announcement, Mori said the cast was more or less set, but ArcS were open to listening to fans, hence why it was announced so early. That'd explain why Ruby was the only cast member shown, since this game must be a while away, makes sense since most of their effort right now is/should be going into DBFZ.
Though, there is speculation - given how they admit the majority of the roster is decided - that we're gonna see reveals starting this month, though no guarantee it'll be RWBY related, since there's a lot of speculation on BB, Undernight, Persona casts as well.
Since the topic of this thread had shifted to the game I just thought I would post what I heard at the RWBY panel at Fan Expo. I don't think the RWBY roster is final yet, though I don't expect a large selection of characters from RWBY.