I guess it depends on how they were looking to do it.
I too am deeply curious about what these alternative Dark Rides would have been like. It seems logical that the Sleeping Beauty one might have pulled a little influence from the Disneyland Castle Walkthrough, but given how much managed to change in Pan, Snow, and Toad between DL and WDW it's possible they may not have been married to it.
I sort of imagine it's possible that Sleeping Beauty would have been a lot like WDW's original Snow, where the story of the movie was followed only very loosely. A scary ride with the emphasis on Maleficent being after you - maybe a quick whirl through the Three Fairie's cottage, with them being spooked by something the way the Dwarves were, and the Dragon bearing down on you from above a room full of thorns instead of the Witch with the giant gem at the end of the ride.
It is surprising that no art has ever emerged giving any sense of what these rides might have been like. You'd think after all this time something would have snuck out that could be traced back to one of these three. I feel like I remember seeing a blueprint with the respective show buildings labeled with these properties, which suggests they were seriously considered at some point, but no concept art for any of the scenes to suggest that they were actively being developed. Makes you wonder how early it was that the decision was made to nix them in favor of new versions of the DL rides.