Interesting, it looks like that Flight schedule is cancelled. A couple of searches show the latest flight is #635 at 12:40pm. Too bad, I remember the good ole' days arriving in Las Americas around midnight from a 7:50pm flight out of JFK (non-stop)
It also looks like they cut the 5:20pm flight out of JFK to STI.
AA has also moved up the flight from Baltimore/POP. i use to arrive at 2:30 but now it's 4:30. they also have a 1 hour change over in San Juan which is crazy because there is a good possibility your bags may not change planes in time. to change over in Miami is to have a layover of 5 hours. i don't know what's going on with AA....