I emailed BBTS on this point a few days ago:

Quote Originally Posted by Response from BBTS
Thank you for your email and I truly apologize for any inconvenience or frustrations you are experiencing with the Preorder items. We did receive a very small portion of the Hasbro Waspintator and sent them out in the set's that were available for Preorder. We are currently working with Hasbro to procure the remainder of our single listing order, and will have an update on our website as soon as one is available.
Urgh.

The frustration for me comes in the fact that Rhinox is paid for and ready to ship, but I don't want to have to pay two lots of postage.