I have bad news for you. Even if the TV is not connected to your WiFi, it could still get into the network over other devices connected via HDMI with HEC [0].
Since all the HDMI connections are via a (slightly older, non-connected) AV receiver, its almost impossible for this to affect my setup. But it's indeed a sleazy move by those setting the HDMI standards.
I'm getting so tired of these constant battles with the devices I paid for.