Those are separate, but equally concerning, things. Connected features are what this article is about, but telemetry is a different issue. On a new vehicle, you might disable the modem but lose several "features," perhaps ones that you effectively have to have.

On somewhat older vehicles that don't rely on connectivity to the same degree, disabling the modem only prevents telemetry data being sent to wherever-it-is that that data goes. That seems to be the sweet spot for me.