Taking them off the wifi and changing your wifi password seems to be all you need to do. While they are technically capable to look for open wifi, this is not something they do out of the box, as far as my understanding goes.
Correct, no one has ever provided a case of this actually happening on any TV model.
But that doesn't stop people from repeating it any time someone gives the incredibly straightforward suggestion to just disconnect WiFi if you're concerned about intrusive monitoring.
