I just got back from a week-long stay there, helping out relief efforts. From what I understand, Haiti was not so poor until a coup in 1986, so I guess when Mike, et al were coming up with Kokomo, Port Au Prince was still a viable tourist destination.
Here's hoping that it can be one day again, but most importantly that the people of Haiti will be able to get back on their feet and have a government that doesn't take all the aid. Maybe Mike can include it again in the inevitable Kokomo "update" song.