I am left wondering if in the last the FCC bookings were fully refundable. I suspect today if you make a booking with a fully refundable Fare, you will be able to change, keep your full deposit, and also keep your OBC for booking on board.
I suspect that if the FCC is book with a non refundable fare, the $200 deposit is lost, the FCC is cancelled, and you do not receive the OBC.
I am not sure what happens if you book a non refundable suite and pay a deposit greater than $200. Perhaps you get to keep the OBC?