They only demonstrated that they could launch the missile using the capsule launch system for the Tomahawk Cruise missile, not that they could actually hit anything with it.

 

A submerged submarine would have to track the target using sonar to determine when to launch the missile.  The helicopter would have to be low, fairly slow (probably <500'), and very close to the submarine for that to work (sound travels MUCH slower than electromagnetic radiation), and the submarine running shallow to launch the missile (which is why this is part of the Littoral Warfare Weapon (LWW) program).

 

This is a specialized weapon for very limited situations.  It most likely cannot be used against fixed wing aircraft because their speed and delays in tracking via sonar.  The AIM-120 can not increase the range system due to this limitations and it's seeker does not perform well versus slow targets at very low elevations.