Most Aikido techniques consist of distinct phases. Zanshin, Ma'ai, getting off the line, taking the balance and then the actual "technique".
Many kokyu techniques I've found are kihon (basic) techniques, but where the timing and blending are emphasised to the point where the balance taking phase becomes the technique in and of itself - i.e. it projects uke far enough that the following up technique is not required.
Example - irimi nage. We cut uke down and when they recover and rise we blend with that upward motion to complete the throw. However if our intial cutting down of uke is powerful enough that he hits the deck like a sack of spuds and doesn't recover, that's a kokyu.