When Keen & Ressler are staking out the initial meeting, they are discussing finding out Red's true identity. At that time, Aram can hear everything they're saying over the radio, yet the show proceeds with still no one but Keen and Ressler knowing about Reddington's secret.
It makes no sense for Olson to be so concerned with security that she delivers her own special self-destructing laptops to her victims to make contact but then uses a video stream to do so, needlessly supplying them with her actual voice and likeness.