I’m guessing that pilot had also been taught the lesson of Avianca 052, which crashed at JFK because the FO / captain did not explicitly declare a fuel emergency.

JFK ATC in particular has an enormous workload with many international flights, combined with direct, even conflictual at times, NY communication style. It puts the onus on the pilot for conveying the message to ATC, rather than ATC for extracting the message from the pilot.