The FCC tends to push all RF spectrum users to move toward narrow band technology versus wide band. With a narrow bandwidth you can get more users in the same amount of RF Spectrum. Consequently, typically wider band equipment tends to be phased out to narrow band equipment.  As narrower band technology becomes available, effective and cost effective, then they typically mandate such moves. Also. sometimes they even mandate the move to force the technology to improve, etc. (e.g. Digital TV, etc.) That being said, this low level RF is somewhat unregulated.

However, ... Now you got to ask yourself; What is wrong with the current narrower band equipment that Spektrum feels they need to go to wider band equipment? Or is this just another a betamax marketing ploy? Just a little food for thought.  Personally, I feel narrow is better. If you have a narrow signal, there is less of a chance that it will be interfered with in the first place. If they really wanted to ensure the signal gets through 100% error free, then they would use error checking and implement that on two frequencies that were far enough apart so the the signals were duplex. (i.e. two-way commo between the Transmitter and Receiver) Essentally the Transmitter and Reciever would both be transceivers (e.g. kind of what they are doing with telemetry).