Well, not quite. In the original Disneyland version, the stretching room is an elevator, due to lack of space within the railroad track boundaries for the show building. By moving guests down and underneath the railroad tracks, this allows the main part of the ride to occur beyond the railroad tracks, free from space constraints. This same system of moving guests outside the railroad tracks for the main attraction was used two years prior at Disneyland for Pirates of the Caribbean (utilizing 2 drops and a lift hill at the end), was used later on for Indiana Jones Adventure (with its lengthy indoor queue), and was even used for WDW's Space Mountain (with its own lengthy indoor queue). However, returning to the Haunted Mansion, as the WDW version was an opening day attraction, space for the show building was not a problem, so instead the stretching room is a normal room, with the effect achieved by lifting the ceiling and the wall paneling upwards, and not moving the floor downwards. The dark room coupled with the visual cues from the lifting ceiling create the effect that you are moving downwards, when in actuality you aren't moving at all. With that in mind, it's entirely feasible for both doors to the stretching rooms to stay open at WDW, though it would completely ruin the effect. With the Disneyland version, this would be impossible.
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