You re right but the author of the post too.
Arôme has forecasts for carribean island, it is the same API than the main arôme one.
I have a software to get those grib because windy does not have it. (It s the best short scale forecast for those island).
Windy is, from far, he best app I ve met for weather for cast. It just lack of this model for thoses islands.
So yes, you could have the forecast for carribean island, it s the same than the other API to get gribs.