According to Wikipedia, a hologram is "a technique that allows the light scattered from an object to be recorded and later reconstructed so that it appears as if the object is in the same position relative to the recording medium as it was when recorded".
What CNN did on election night was take an all around picture of someone and put it on a TV screen. There was no 3D image in the room with Wolf Blitzer. There was no flickering Princess Leia you could stick your hand through. This is not a hologram. This has no relationship to a hologram.
I don't know why anyone thought that it was a big deal to put a picture of someone on a screen. We've been doing that for a very long time now.