There isn't always a studio behind a videos release. Sometimes the only remaining copy of a show is found in somebodies VHS collection and its filled with static and audio pops. These often get a standard 'as-is' release and then somebody in the community will clean it up, upscale the video, and fix the audio for a 'proper' release. Same goes for audio, sometimes its a old bootleg tape of a show that gets digitized and cleaned up.

This is before even getting into 'fan edits' where people will re-add cut scenes, or do other edits to films. For an example of that, search for 'Topher Grace Star Wars Prequel'.