That's probably true for later generations, but in the NES (and maybe SNES) era? Undoubtedly, they didn't have the foresight to write that into the contracts.

In the early days of television, many broadcasters were prohibited by contract to retain any copies of the performance, because no value was seen in reusing them, and there's no other reason to give them any rights. Also see shows like WKRP in Cincinnati where music was only licensed for the slim purpose of the original broadcast (and perhaps direct repeats in syndication), but for release on home video, the music used did not support that use, so it had to be replaced.