Yes, you can be sure. The network capabilities aren't hidden spy equipment. You can disable WiFi and simply not connect Ethernet. The market for your data is relying on the indifference of 99% of TV buyers to data collection. Manufacturers and advertisers -- at least those not too far down the grey market rabbit hole -- don't care enough about the tiny fraction of people that actively thwart this collection activity to employ some sort of legally dubious super sekrit network capability to capture your precious data.
Ethernet over HDMI is a thing, isn't it?
* https://apple.stackexchange.com/questions/325215/appletv-eth...
Unfortunately, outside of rural areas that may not be under your control.
It's not something that should just be left up to chance, but I also don't know of a good solution other than regulation.
Some enterprise systems don’t require users to enter passwords, but the software still uses them internally when talking to the network.
PS: Unless you know of some other exception?