Not new
I do not know this two specific ones, but there are adult vacation stops like this around the Caribean and Asia all over, in fact a number of them have been fetured in a number of reports including Playboy's Sexcetera.
Just do a search on the web and you will find a number of locations.
I have done 2 one in Baja in Mexico (Mostly Mexican women, some European, some North American) near Los Cabos. The place was clean and relatively new when I visit, not lots of people so it was not bad.
The second one was in the Dominican Republic 9but not the one you mention) owned by a French guy with mostly European (Eastern European) girls. More upper class in a private beach setting.
I did the second with some friends, in fact a body of mine organised, did the second alone on a tip from another friend becaues of the closeness to my city.
If you can click with a girl or girls there, it is quite fun and relaxing, knowing everyone else there is doing the same also helps. But overwhelming to me was the level of fun I had with my buds as compared to alone, if you can get a group of guys going with some no - inivitions girls going, well you can have lots of fun.
Another idea I would like to experiement in the future is going there as a couple, that has to be fun as well.
Hope this helps