My money’s on a joint venture with Comcast, Cox, Verizon, et al. to use the Wi-Fi access points their routers operate – even if you use your own router and block them, your neighbors almost certainly don’t. Most them already have business ties and would love to have better ad targeting data.

Man, at that point I would open up the back and snip/desolder the antenna itself. I hate ads on my TV, ESPECIALLY when I've already paid for the damn thing!

Sounds similar to Amazon Sidewalk...

That's highly speculative, but even if that did end up happening, the smart TVs sold today wouldn't magically gain that capability, especially if you keep it off the network and never update it.

Or 5g with a SIM card.

Fine with that, free data on my modem

You won't be able to remove it. It will be an eSIM.

Already happened with cars. That's what OnStar was/is.