Keep in mind that we can only see what the Mil is willing to show us (and the rest of the world) and is subject to the limits of the ADSB servers. Earlier I logged onto ADSB and there were only 3 planes showing for the entire country and TWO of them were over Mar a Lago.
That's bullshit. Then, 15-20 minutes later, the sky got crowded with many planes already over 30k.
While it's possible that there are, for a brief interval, no E6s, what's more likely is that there are no E6s -showing-.