Well Fuji do still sell one black & white peel apart instant film, so must have the know how to do a B & W instax film if they chose. However as apparently they couldn't make a profit from their excellent Neopan 400 35mm film, I can't see them introducing a B & W film in instax formats. So I don't think the Impossible Project have anything to fear.
Yeah, I think Fuji makes more money with their FP series because they are the only ones doing it and the Instax arent selling as much. At least they released a new mini cam. Maybe that'll spark some interest.