Some multimedia content is accessible even without audio description. They can be understood without any problem from the background sounds, narration, etc. Setting this success criterion to be level 1 or 2 can cause redundancy the information provided in audio, and may hinder the accessibility of such simple content.
Make this applicable only to those content that cannot be understood without audio description. There may be a discussion how to determine if piece of content is accessible without audio description, but that should be as easy as determining if added audio description insufficient to make the content accessible.
If the audio track provides full information about the video (as in your example) then it is accessible already and no Audio Description would be necessary. We have added a note to G78: Providing a sound track that includes audio description that describes this exception.