Many games these days come with explicit terms allowing streaming of the game content, including the music. But this, and your argument, is not really very related to the case at hand.

In addition to the alleged GPL violations, there is a real contract dispute here. Vizio also included a written offer of source code to the GPLd components of their software with the television. The SFC tried to avail themselves of that offer by writing to the address given, but Vizio denied their request. It’s a straight forward open and shut contract case: Vizio made a credible offer (and thus created a contract) and then failed to uphold their end of the deal.