They are officially the "5th place play-off" (actually determining 5th, 6th and 7th place) of the CFU Caribbean Cup. Perhaps the Caribbean Cup finals will be used for seeding purposes for the CONCACAF Gold Cup? But yes, they are not "qualifiers" in the strictest sense, as all 4 teams have already qualified.
Meanwhile, Trinidad & Tobago used up their 3 subs in 90 minutes against Suriname, and then brought on a 4th sub in extra time. Not sure that is allowed in continental qualifiers/finals matches.