As long as the chance to drop is not equal 100%, there is a probability that you will never see a key dropped even when running MP9. And I mean never in your life time. The chance is extremely tiny, but it's not impossible - however, if we account for how generating random number in machines works, that means it's not truly random, this does not apply to D3.
What I wanted to prove is that RNG is just RNG. Sometimes you have bad luck, sometimes you are blessed by the RNG Gods.