It's to free up bandwidth, there's only so much room and it's getting cluttered fast.
Police,Fire,Rescue, all of these use a lower frequency so as to not be bothered by buildings,trees and other things.Satellite communications are in the GHZ which is higher than regular radio communications, but if you ever notice that it's easily blocked by trees,buildings and whatever. You need a direct line of sight with satellite communications, not with radio communications.
Notice on the chart that our vision (what we see) is above infrared and below ultraviolet.
Behind every move of the government there's a conspiracy theorist, but that doesn't mean there's an actual conspiracy. This is a move to simply free up bandwidth for other uses besides TV. That's it!