That is neither what I am suggesting or what others are suggesting g.

It’s real simple, maybe your PhD is getting in your way.

For most people, the word earthquake means the earth is shaking where we are. We aren’t dumb, we all understand that the actual seismic plate slip or whatever happened a thousand miles away or something g, maybe way deep in the earth. And we aren’t dumb, we all know that the wave travels through the mantle and the crust at different speeds to get to different places at different times.

What the OP said is entirely true. The earth quakes at one place, phones detect it, and they tell other phones that an earthquake is coming to their location in like 10 seconds.

OP is entirely correct. They are predicting earthquakes based on other earthquakes.

Your usuals of the word might be correct in the technical parlance, but it is wildly incorrect in the popular, common, context. We all get where earthquakes come from, but none of us is calling the event way down in the earth the earthquake.