This is great by Cuba, but I will defend those islands who refused them a little. A lot of those places have substantial populations of very poor people who live in tight, poor conditions, and they rely entirely on imports for almost everything, especially medical supplies. An outbreak on an island like that, with every country trying to source the same supplies and no where for any of their people to go, would be an extreme disaster. And one that no other country can really help with at the moment since we’re all dealing with it.
Cuba also has this issue of lots of poor people, but for all the (in many cases deserved) shit they get, they are known to have great healthcare, so hopefully they are equipped to handle this. Props to them in any case.