Its always speculation that would be trivial to actually test.

1. Do not connect to network 2. Create unauthenticated WiFi network 3. Monitor WiFi network

Strange no one has ever done this simple af test to backup their claims

If TV manufacturers wanted to be underhanded then they could actually make this much harder to detect by delaying the connection to new unauthenticated networks for e.g. months or only after seeing another device connect and then using that device's MAC when it is not around.

Still super easily detectable even if they clone a MAC.

I have an unprotected guest network with a captive portal and an LG C1. I have never seen the LG pop up in the logs for the guest network.