In that case, jailbreak it, or open it and unsolder the wifi antenna, or put some well placed copper tape until you no longer see any wifi traffic from the TV from other wifi capable devices running a wifi packet inspector.

The TV belongs to you and it will obey you with modest effort.

Basically don’t buy Samsung or LG if you really care.

I want to know how to disable their external communication via wifi, I'd like to see how they are exfiltrating info. If I don't connect them to my wifi, apparently they connect to Xfinity wifi at your neighbors house.