If you are staying at WDW after your cruise, you will have time to go to a park on debarkation day. Arriving around noon sounds right. I prefer to Rope Drop on Magic Kingdom day, so I can get through several rides with minimal crowds, so I would choose a different park with fewer rides for the first day, but that's a personal choice. The ship should dock by 7 am, so you should have cell service to use for
Genie+/LL if you want.
I agree that if you want to arrive more quickly, you could use private transport, and that renting a car (although you'd have the additional time to get to the rental agency) would allow you to leave luggage in the car and delay stopping at your resort until after you'd spent time in the park. (That assumes you don't need to worry about temperature control on the luggage.)