No New York City, and definitley not San Juan.
Likely, the 763 that sits pretty in Bunoes Aires all day between Dallas flights will be utlized to start a third daily Miami-Buenos Aires flight that will operate during daylight hours and not require additional aircraft.
This also makes Miami-Cordoba a possibility. Like this winter's proposed Miami-Asuncion and Miami-Salvador services, it would probably operate as a redeye to COR/a daylight from COR with a winglet 757.
Other options exist, but I really doubt they would try for anything else.
Interesting to see what AA does. They can apply for both.