Well, it say "All Fly2Fun bookings come with flight protection — free! That means you’re covered in case weather conditions or flight changes delay your arrival to the ship. We’ll make alternate flight, hotel and/or ground transportation arrangements and do everything we can to get you to the cruise port in time to board the ship, at no expense to you. If no viable options are available to get you to the ship before departure at the homeport, you will be given a Future Cruise Credit to use toward an alternate Carnival cruise."
If I book direct through the airline and they cancel the flight or the weather is bad and causes cancellation or delays, the airline themselves don't care about whether I miss a cruise or not.
I guess I'm wondering if booking through Carnival actually gives me a little more peace of mind and coverage if there is a cancellation or delay. Our winters are known for being rough, travel-wise.