I don't know if I'd say it is unfair. They may have had to do it for logistical reasons, and canceling a port is not an exclusively RCI thing. They all do it. If you use this as a criteria for canceling cruises you will quickly be fresh out of cruise lines! Also, by definition a trans-Atlantic cruise means mostly sea days and not too many ports. I just looked at the itinerary and don't see what is unreasonable about it - but then I prefer sea days to port days.
But beyond that - if your cruise is not until April 2009 I can't understand why you wouldn't get your deposit back. Here
is the RCI refund policy. Perhaps they misunderstood and thought you said April 2008?