It wouldn't even need to use any sort of standards-based DNS-like thing at all, if they control the server (on a stable IP address in the TV's firmware) and the client (the TV). It could be any data scheme (probably https for simplicity and blending in) along the lines of "give me all the other IP addresses I'll need, which aren't as stable as the one in my firmware."

Regardless, what is the benefit of putting the TV on the network but preventing it from doing DNS lookups anyway, even if you could be sure you succeed?