They could have a placeholder that they used when they booked their current cruise. I know that if you don't use a TA and get a placeholder, you have 30 days to move it to a TA, if not, you have to book your cruise through DCL to use the placeholder.
Psy
Does placeholder mean reservation/deposit? I think I am missing something. I guess if you didn't know you could transfer to Costco and get the additional benefits but if you plan to transfer, why go through DCL (or any TA) at all?