Questions concerning rebuilding have no relevance.....
Devastation aside. Cities are world-wide located because of the diamond value of real estate---location. The Mississippi river has a depth of 200ft. at the Gulf confluence. This makes the ports around this entire area virtually unrivaled for this nations shipping.
Not rebuilding is not even an option. Nor, has it ever been. And for the historical interest, the Vieux Carre was virtually untouched. Remember the cry, "the South will rise again." They certainly haven't forgotten it along the Gulf coast. As hearbreaking as the losses are the spirit of the people require re=building.
And if you look back in history, most of the great cities of the world have suffered some sort of devastation and have been subsequently re-built.
Publius