My theoretical attraction would be a "villain ride;" a bizarro version of Snow White where nearly all the focus is on the Witch, but still with the familiar locales and art style of the film, as well as several appearances of the Dwarfs. If you're interested, I wrote a detailed description of the entire thing back in January in this thread:
https://forums.wdwmagic.com/threads/ideal-dream-versions-of-existing-disney-attractions.971327/
The point of the ride is not to treat guests to the story of the film, rather put them into a fun, perilous scenario in which
they assume the role of the damsel as the Witch hunts
them down instead of Snow White. This is the same basic philosophy used for any Snow White, Mr. Toad, or Alice dark ride designed prior to the 1980s. Those old attractions each lacked in-ride appearances of the main character (this is still true for Toad), as
you the rider were meant to assume their role. Here, however, it's far more excusable, as the ride is explicitly and obviously themed around the Witch alone, so there wouldn't be much of a reason to expect an appearance from Snow White to begin with.
Snow White has been done to death; it's one of Disney's most iconic features, and Snow White and the Dwarfs are certain to have a presence in any Disney park via walk-around characters regardless of whether or not there's a ride based on the film. For these reasons, you don't necessarily need the character of Snow White to be in a dark ride based on the film.