They are already doing a beast-ish line with many of the Con RID characters and just before that we had the Beast Hunters cartoon and toyline. In the Titans Return line there are a few beast characters like Ravage & Stripes. Throw in the odd BW homage Generations toy and MP Primal and I think beasts have been pretty well covered over the last few years.
Oh, and Takara are rereleasing those characters that you mentioned very soon as part of the BW 20th anniversary.
As for Armada, I don't think we will ever see a 'plethora' as it was popular but not that popular. We may continue to see the odd Generations character based on the line though. So far none have been as cool as the original Armada toys sadly.