With the destruction in Miami, gulf coast and Houston there's only so much in terms of federal resources to go around.
Midterm elections coming in a year... Who are the politicians going to allocate money to? The people who can vote them out of office or Puerto Rico?
By all measure Puerto Rico's infrastructure was already a complete shit show before the hurricane. Because of it's location and what's needed to fix it, it's going to become crazy expansive very quickly. To add to that, with the poverty and debt that PR already has, I don't expect investors are going to line up in droves to dump money in.
Will PR get rebuild? Yes. Will it be slow as shit. You can bet on it.