Ultimately based on the results of the simulations I feel Blizzard made the right decision in treating Necrotic Strike the same as other sources of damage, and I hope it remains this way.
However the question of who will benefit the most from Dampening remains. The simple answer is players who depend on mitigation and avoidance for survival rather than healing or damage absorbs stand to benefit the most, I will leave it up to the community to debate that for the time being though, this post is already long enough! I hope this analysis has been helpful in understanding how Necrotic Strike works and how it is affected by Dampening. If you have any questions please feel free to ask and I will do my best to provide an answer.