You have to watch out for the TVs that attempt to connect to public networks. So pray your neighbors have passwords on their wifi and didn't opt in to Comcast's hotspots.
It should be hard for the TV to recognize what you play connected from a cable. (Edit: I know they can do it but please read the next paragraph).
Besides, if you block commercials from the smart features, what does the manufacturer gains by spying on you? Without incentives why bother the work?
https://www.privateinternetaccess.com/blog/samsung-smart-tvs...