On the always-amazing Passport to Dreams Old and New, a fantastic piece of detective work about the evolution of the Walt Disney World Haunted Mansion. FoxxFur starts with the observation that the traditional story about the Florida stretch rooms going up (unlike the California Mansion, whose stretch rooms descend) is that the water table was too high to permit a descent, but quickly demolishes that. From there, she undertakes some remarkable detective work in exploring the inspiration and thinking that went into the Florida Mansion's design.
I think what happened is that once Claude Coats knew he would have to re-design the facade to sit at the same level as the load area, he simply transposed the layout down. The second ticket and holding area would now be useless as well as in the way of the exit door, which would now sit at the same level as the entrance door, so he got rid of it.
The Florida Haunted Mansion facade is really a pretty ingenious case of form following function; in this case; the form was already determined by an aborted elevator configuration. The Florida facade is actually very tiny; only large enough to accommodate the stretch rooms. The Foyer area is disguised as a stone pedestal that the house sits on, and it's buried in dirt on two sides, further disguising its function. This construction photo, paired with the layout above, pretty clearly shows how the Mansion itself is really just a tiny wrap that conceals the empty space that the dual stretch rooms are hauled up into: In fact, the biggest change is that the entrance door now faces west instead of south - it's in the exact same spot.