They are fully in compliant with the Town of Hilton Head's policy. The DVC Resort has opted to expand their own policy beyond the town's, as is their right.
End-of-Story.
The state of South Carolina has never had a mask mandate in place. Individual counties, cities, and towns have opted to initial and enforce their own policies. Hilton Head Island is one of those communities with such a policy and Disney's Hilton Head Island Resort is within the area covered by that policy and even made their own policy a little more exclusive.
You can say "The DVC Resort has opted to expand their own policy beyond the town's, as is their right", and "The DVC resort cannot change their current policy until the town modifies their current policy, and, even then, the resort may still continue their policy as their own choice", but you can't say both of them. One is true and one is not. You are very against mask disinformation and like to close down dissenting threads, but here you are with two conflicting statements back to back. One statement is disinformation, which one is it? End-of-story.