If the previous owner's BIS account is still active, yes, the service books will get pushed again. Also, new owner can not setup new BIS account until previous owner has canceled his BIS account. Hence Dub's suggestion to make sure the old BIS is canceled.

But if there is no data plan associated with the BlackBerry, then deleting the service books would be sufficient. No service books will be pushed again because there is nothing to be pushed.