There will definitely be MIA/HAV flights but lets not for get there is zero business traffic there so it's all humanitarian, family or, leisure travel. (for now, until McDonald's moves in!) After the initial surge it's going to be just another Caribbean destination.
Initially there may be some extra flights just because it was an essentially impossible destination for most Americans, but 2 years from now there will be 2-5 MIA/HAV flights, and maybe a few other destinations, DFW, ORD or JFK but probably not even all 3.