OP, from your post sounds like you typically arrive for your cruises in advance but can't for this one for whatever reason. So I'll leave all the horror stories of delays to what have already been provided, you are aware of the risks if you usually come in beforehand. If you have to come in the day of the cruise -- do a little research yourself before you commit to the time change Delta is giving you. Your 11:30 arrival time might be the best option -- and if all goes to plan be plenty of time to get t the port in time. (I'd say if you land by 1:30 you would be okay to get to the port with some breathing room.) But questions to ask yourself before you commit to the schedule change -- is it non-stop or is non-stop available (remember in airline speak direct and non-stop are different). If it is a connecting flight, do you have a good connection -- is it too close where any slight delay may make you miss your connection. Are you connecting in a city where there are a number of other options available if you are late or your connecting flight has any delays. (It might be better to leave 1/2 later to get a better connection, so look at the options.)
Good luck and as others have said, with Delta, this may not be your last schedule change before you cruise.
Good luck and as others have said, with Delta, this may not be your last schedule change before you cruise.