I think what they were talking about is the TV actively scanning for similar models and connecting to those to reach the internet. I’ve read similar articles showing how smart TVs will even connect to an open WiFi network to try to get online.
All this would bypass your LAN restrictions of course.
Have you missed the other comments? It’s pretty well documented that the TV will either find a similar brand TV to connect to (and reach the internet) or as I’ve read, it’ll find an open WiFi network to do so.