I love Buffet too. I was disappointed to see him hobnobbing with the leftists, but he's an aging, dope-smoking hippie, whatcha gonna do? Was that New Orleans song he played a reference to Katrina?
Anything related to New Orleans is going to have some Katrina overtones, but nearest I can figure, it's because Bradley was a big jazz fan -- he hosted Jazz at Lincoln Center for a number of years, hung out with the Neville Brothers, and performed with them (as well as with Buffett) a time or two. It may have been a request.