When Disney built Castaway Cay they KNEW it was in a hurricane prone area so I'm sure they built all the structures to withstand hurricanes. I know the island took a direct hit in 2004 and if I remember correctly it was only out of service for a week or so. Once the Matthew is out of the way they will probably send a crew via helicopter to survey the damage and then get busy inspecting and repairing. As soon as the island is safe for guests and the channel is safe for the ships to dock they will be back. It's possible that parts of the island may be closed the first couple of weeks but I would think that the family beach and Serenity Bay will be open.According to Wikipedia it took Disney like 18 months to build Castaway Cay no? If the beach lines are ruined, if the housing CMs are living in damaged, the dock, etc out of service, man I don't know!
How many CMs live there? 100? 200? If Disney has to restore all their homes, redredge the beaches, etc. it could be one week but could easily be next year in my mind depending on damage.
It's taken them 5 plus years to build Pandora on mainland US. I just do not equate Disney with speedy.