My first thought is: this is probably just coincidence. It was just a useless completion that normally would have gone totally unnoticed except for your recent

My first thought is: this is probably just coincidence. It was just a useless completion that normally would have gone totally unnoticed except for your recent conversation about this person. It seems possible that a phone might be continually listening to background chatter and trying to extract salient/useful pieces of information to then feed into predictive assistants... but honestly that seems like a lot of computational work (especially on a device known for excellent use of its power budget), and a lot of development work. All for a very small incremental improvement in assistant UX that is probably not going to be noticed by most people.