Here's the rest of the story. Back in June I purchased my ticket (BOS-FLL-SXM) using points for January 5th. Two days ago I received notification that my flight had been changed to BOS-JFK-SXM.
The reason the change was due to changes in the departure time from FLL - it was only a few minutes, but brought the time for making the connection to under what Jetblue requires. So they made the change. I'm still not happy. I deliberately booked through Fort Lauderdale to avoid any weather complications in January. Additionally I now have a 3 hour connecting time in JFK. I remain suspicious as the flight BOS/FLL was shown as "sold out" almost immediately after my flight change. But there appears to be nothing I can do about it as attempting to re-book at this point has very few options. I hope I've clarified my situation. Thanks to everyone for their input