I'm not surprised that Thanksgiving traditions in Puerto Rico are different than here in New England, but yes, Puerto Rico is a part of the US and therefore I expect it to have the same idiosyncratic US-specific national holidays we do here. For example, I assume there's a Labor Day in October in Puerto Rico, too. Although there's an international Labor Day as well, that one's on May 1st, and the one in October is US-specific. I also assume Puerto Rico has a 4th of July holiday, etc.