There are other attack vectors of a TV. For example, most TVs have a usb.
Imagine an attack in which an attacker gains physical access to your TV and loads malware onto your TV via USB. Now the infected TV is communicating with a nearby WIFI hotspot to upload the audio recordings from the TV's microphone (that exists for voice commands).
I think the TV is malware out-of-the-book if connected to a network connection. Either way it's actually a huge vulnerability.