Well, I will say this.
The word is it happened yesterday.
Yesterday, if during the day, my kids were in school and the school would have gone into lock down (procedural)
My parents also came in on a flight yesterday. All was normal then.
That is all I can offer up.
That's if and only of if, they knew then.
Article says the flight took off at 6:05 PM, but playback of traffic from JFK shows it taking off about 6:40. Of course that would be about par for the course if scheduled TO was 6:05. The playback does show one rather odd, two segment, turn to fly toward Philedelphia, which it skirted to the north.