Good analysis
However they will rebuild at least part of it. The Port is definitely important enough to rebuild and the French Quarter wil be restored.
According to a report I heard, the French Quarter sits on some of the highest ground in the area. Looks like the French of old did show signs of intelligence building there, wonder what's happened since?
The port is important of course, but is that the best place for it. The flow of the Mississippi past NO is artificially maintained by the US Army Corps of Engineers. Left alone the river would be flowing down what is now the Atchafalaya River. It costs big $$ to keep most of it flowing past NO. A new canal could be dug parallel to that river to take enough of the flow to maintain a good port, say in the vicinity of Morgan City.