Honestly sounds very legit. The FLL flight times have been played with. I did the connection once and it was a 6 hour layover. Now you can’t book it because of timing. Honestly I worry more about FLL and their thunder/rain/lightening storms than JFK and weather and they are really on top of it and it has to be real bad to close JFK. Just like Boston. Plus clearing in terminal 5 is “usually” a breeze.