What do you mean “figure it out”? I’m not familiar with the example, but this sounds like a fairly simple application of ML. At the end of the day it is just finding trends in extremely large datasets that humans don’t have the brain power to process. Just because humans can’t do that work doesn’t mean we can’t understand it.

For example with predicting the pregnancy. A human might try to predict this by working backwards. You can first just try to understand the persons age and if they are female. Not too crazy to figure out from purchase history. Maybe you see that the person is in a relationship because they started buying Mens shampoo. Maybe they started buying dogfood and you find in your training data people tend to have a child within a few years of getting a pet. Tons of little things that can point you in the right direction. Now a computer is just doing this but ramped up to the max. The applications are very simple, the computation is the part the is complex.