How many open WiFi networks are there within range of your TV?
Comcast runs a separate "Xfinity WiFi" on all their routers, any Comcast user can connect to it with their credentials. Would they strike a deal with TV manufacturers to let them use it? It would not surprise me.
Pretty sure this is a known offering from Comcast, you just have to talk to the right sales rep... I haven't yet seen any evidence of a TV using it (yet), but hve been told they will sell a company IoT or fleet device access to their wifi endpoints for enough money. I'm not sure it would be cost effective for mass market device surveillance, though.
Also Amazon does this same model with their Sidewalk service, which can run over bluetooth or lora, instead of wifi... and is specifically priced to be usable for large numbers of devices.
It would however surprise many.