Part 4 of the new storyline in the BT series has been posted to the allspark board.

http://www.allspark.com/forums/index...howtopic=51739

Includes a cameo of sorts of Optimus Primal, after his death in Beast Machines. These BT stories are fan-written, but being on official product packaging, it effectively makes it canon that BT is in the universe of BW/BM.
And being fan-written, it doesn't mean that any other character mentioned (like Primal) is going to be released in the BT toyline.