I'm confused about the "reality" aspect of HM before the advent of the queue addition. What about the hearse parked out front attached to an invisible horse? The errie wolf cry? The use of bat imagery (the weather vane, the arch above the gates, the maids' hats), the original cemetery with funny inscirptions, the thunder/lightning effects at night that happen when there is no real rain, the attraction plaque with demon and snakes, or how even the house itself is designed to look like a monster about to pounce on you?
Are these supposed to be hard? Point by point.
The hearse parked out front As you discover inside, it's a retirement home for ghosts. Evidently, one of them arrived with his commandeered real-world hearse (poltergeists steal physical objects all the time) and his ghost horse, and he absentmindedly left it parked out front. Incidentally, I hate that thing. Jumps the gun by displaying a ghost before you even get inside. Bad show pacing.
The wolf cry There are no wolf cries in the real world?
The bat imagery Someone who lived there evidently liked bat imagery. So what? Lots of Victorians were into the macabre big time.
The original cemetery with funny inscriptions They don't have witty, macabre epitaphs in the real world?
Thunder/lightning effects at night when there is no real rain It has to rain to have thunder and lightning? Since when?
The plaque This is like safety bars, stroller parking, green EXIT lights, and warnings about flash photography. Necessary evils, accommodations to the fact that this is a make believe world existing in the real world. It's the price you pay for getting to have one of these things. Whenever possible, they try to blend such elements into the background stylistically so they don't stick out so much. So the sign telling people that this is the Haunted Mansion ride is a nicely designed plaque. But that's all it is. You screen it out like the EXIT signs.
The house itself is designed to look like a monster, etc. The house design is based on a real house in Albany, New York, built about 1840. No longer standing, alas.
And before anyone screams AHA!!! about the "make believe world" line, remember that a
depiction of something is make believe. Here, you are going to make believe that ghosts of all kinds exist in the real world.