Nope. NPS is a measure of satisfaction. You care about the word of mouth component, but it isn't measuring something different than retention.
Whether those two happen to coincide is quite product-dependent. Finding examples where they significantly diverge is trivial.
Did people want to tell their friends? Yes, but not because they loved the product. Because they wanted to be seen as cutting edge.
Most of the product hunt/tech crunch circle jerk is stuff like this. Lots of fluff with short-term spikes but little long term retention because the product doesn't solve a real need.