I'm not sure if this has been raised anywhere. Most of the times I watched Teh Hobbit was in the early 80's from a videotape recording at a friends' house. He recorded it in '77.
It opened with the network's caption of "This film has been edited" that many theatrical films carried when broadcast on network TV. I've never gotten an explanation as to why this might be there.
Does anyone have similar memories of even an explanation?