I surprises me if that would not be standard practice for any senior member of the administration! Surely they don't broadcast to terrorists where they are?????
It's not feasible to blackout a flight. Only thing you can do is avoid telling anyone who is on the flight. All planes show on radar and planes with their transponder turned off will just cause air traffic control to send the military to check them out. Even the NATO planes operating around Ukraine can be seen on flightradar. The only exception are military planes flying a combat mission.