Wanted to give an update with my family's experience-
We just returned from an amazing cruise on the Fantasy. My family of five drove to PC and stayed the night at a local hotel with a stay, park and cruise package. We are Silver and planned to meet up with the "Grannies" (my mom and mil) on the boat. They were taking Disney transportation from MCO the morning of the cruise. I never dreamed they would get to the port ahead of us, but they did! Our shuttle from the hotel was delayed (due to port traffic) and we actually didn't arrive at the port until an hour after our PAT
The "Grannies" arriving from the airport had a seamless journey but when they were checking in were given boarding #18. Fortunately for them the CM checking them in said, "since you are the Grandmas I think you need to get on the ship a bit earlier" and replaced their #18 with #8! They boarded the ship and had already booked spa packages and taken care of a few things at guest services before we had even made it through security!
Moral of the story, however-seems that while Disney transfers might be convenient to getting to and into the Port it no longer means a guarantee on a low boarding number. They clearly got lucky!
I'm going to keep watch on this thread to hear others experiences.
Happy Sailing!
-Kelly