This is what we can expect during a large scale disaster.
By contrast, the hurricanes which hit our southern states did not stop the arrival of freight from areas outside the impacted areas. No so in Puerto Rico, because the entire "island" was in the damage zone. There is no "outside" which was unaffected.
There are two means to reach P.R., by air, or by sea. The airports are still being cleared and the ports are in use, but as noted in the linked article, the rest of the transport infrastructure has not recovered.
At the same time, it is NOT wise planning to expect rescue and aid to arrive at your location, post disaster. "Prepare for the worst, hope for the best"...
Personally, my plans do not depend on outside aid. In fact, I would be suspicious of an offer of aid
during the early part of a "recovery" period. It is too likely to be a false offer, intended to gain access to your location and your supplies. It could also be an offer to enter a "shelter" managed by government agencies...
"We're from the government, we're here to help".
Paranoid? Yes, I am. If you cannot manage full paranoia, at least learn some healthy skepticism.