This reponse is hypocritical and contradicts your previous comments, talking about the "we were in the neighbourhood" situation, which you repeatedly emphasized was a TV trope.
You call my comment "meaningless" but I would call yours meaingless because you seemingly make it impossible by defintition to have an unplanned meeting if there's a phone involved. If I'm in my car parked in front of your house and call to ask "are you home?" does that magically become a planned rather than unplanned visit?
An example from another thread: "if you’re equidistant between your house and your friends house". A phone call or text while you're out and about does not transform a visit from unplanned into planned. All it does is give a little advanced warning—a few minutes at most—of the unplanned visit. There's obviously a little more courtesy in calling on a mobile phone and saying "I'm in the neighborhood" as opposed to showing up at your door and saying "I was in the neighborhood", but the mobile phone doesn't add planning to the equation.