I think a lot of Puerto Ricans that leave the Island will end up in NYC which won’t change the voter dynamics there. South Florida has a large Cuban Migrant population, but Puerto Ricans tend to gravitate towards NYC.
It seems the more recent migration waves from PR have moved to FL especially the Orlando area.
You have not been in the Orlando area lately, I suspect :-) and I would add one other thing, which is that any major migration to FL from PR will exacerbate the endoHispanic animosities among the Cubans, Mexicans, and Puerto Ricans, which in the inner cities of Tampa, Orlando, Jacksonville, and Miami will lead to greater incidents of violence, I fear.
True...this is just jumping to conclusions. Plus many PRs are pro Trump