Welcome to cruise-chat.
Currently, Royal Caribbean has not invoked the fuel surcharges. My thinking is even if they do, they will do so only for new bookings and will not retroactively charge people. That was a public relations disaster for all the cruise lines, as well as a legal mess.
If your cruise is within a few weeks I'd say you are safe. No guarantees, but oil dropped almost $10 per barrel this week so that is a good thing.