Sorry guys for the little misunderstood,
You know that it would be unrealistic to says that every soldier would have them all the time and this was my mistake. But, With the buy rate that DND is going through with the new one. It will probably be issued on the large scale. From what i heard (Unofficial). They are planning on Section commander, 2I/C (Infantry) and up. Plus all attached Sigs(Part of the comms gear). As for other unit type(Field Amb, SVCS BAT i dont know).
Those GPS unit do a little more then map and direction (Like the Old Unit, But we can't talk about those options here), but is much more user friendly and dummy proof. As for map and compass, I can tell you the new Sigs generation don't know much about them anymore. They don't teach that much anymore.
As for jamming GPS, or making display the information you want. It is very easy. And you can get the equipment on ebay. Nothing high tech there.
The easy way to put it, the signal from a satellite is very low power and not encrypted when it reach the GPS(Civilian), So you just have to transmit what you want at a higher power output in the area you want for any GPS to receive. Basic Electronic Warfare. It applies to everything that use radio frequency even satellitte. The danger is really there.
But yes, the new model will be widely distributed, As part of kit.