Not really true. Puerto Ricans only started coming to Boston in earnest in the 60s... after Hurricane Maria there was another large wave but their in-migration to Boston, in general, only slowed in the 2000s. That is fact.
Puerto Rican outbound migration ended in the late sixties. When it resumed in the New Millenium, it was to Orlando, Atlanta and the Southeast, not the Northeast.
I would categorize any Latin music eliminating from the Carribean as ‘Tropical’. Unless you know of “reggaeton” or Spanish folkloric” stations...
Tropical means dance rythms like cumbia, porro, gaita, vallenato, salsa , merengue and the like. There is plenty of music from “the tropics“ that is not “tropical” such as pasillos Fromm Ecuador and bambucos from Colombia and “música jíbara” from Puerto Rico to name just a few.
Central Americans do have some things in common with PR and DR, and often do listen to regaeton like a Roachy D or El Alfa, but more heavily favor “classic” Latin music
And, yes, Julio Iglesias and José José to name a few were popular all over Latin America. But the Greater Antilles is Afro American in its cultural influence while Central America is pretty much the opposite, being racially rooted in indigenous peoples.
While pop and rock are fairly universal, that is mostly upper income class appeal, and not preferred by most improvement-seeking immigrants who like local or regional music types.
. In DC, much if not most of the music played on 107.9 is Dominican in origin despite it being an extremely extremely salvadorian CSA. Central Americans work to assimilate int the larger more established populations, much like Black immigrants do towards black Americans
The Salvadorian migration to DC began in the later 60’s an is now third generation.
Partially vs largely is a vague argument/distinction to make.
There are no universal Hispanic formats that are totally viable today for everyone, with reggaetón and rhythmic being the broadest. No tropical music is any more than national or regional, but not universal.