Thinking back to Jimmy Fallon and F&F with the no switchback queue, what if the luigi mansion/bowser's airship are part of the queue now to expand the scope and not individual attractions? I mean Mario Kart queue would have to be quite long to hold all the people who might want to ride and due to Potter and how much people enjoyed Fallon's queue system.
If you go back to the USJ SNW concept video you see the land technically has three visible floors and not just two with people mainly only able to walk on the first and third level outside with only a little of the second level in front of the castle being able to be used in the trailer and if you back to the concept art, there is a exit/entrance on second floor stairs by Yoshi (see where the question mark box is next to the mushroom on the stairs, you see a guy walking towards it. If you also watch the SNW trailer you can also see an entrance of some kind as well at 0:12. If you also look underneath it next to the mushroom house is a weird brown square with people walking into it.
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Combining both the concept art/trailer...there are 14 visible entrances/exits, not including the bridge and assuming the castle doors don't open (including those raises it to 18 entrances/exits) So you have one for coming into and leaving the area which is the warp pipe on the bottom left corner of the trailer and blocked by the Universal logo on this concept art. That leaves 13 left. With most USJ lands having two bathrooms assuming this will be the same, that leaves 11 entrances/exits unaccounted for. Then you have Mario Kart/Yoshi so one entrance and one exit into a gift shop, you now have 7 entrances/exits remaining. The castle has one big ingress/egress which makes me assume its something many people will come in and out of so that's either a food court, or a show area or an entrance but wouldn't make sense with the wrap pipe. That leaves for 6 entrance/exits. Each could be its own store/restaurant/or some may share. Then again, they could also be for something I'm not thinking of yet.
There are some differences though between the concept art and the trailer. This Concept art has Yoshi's on the bridge, The trailer had none. The video also had a courtyard in the middle of the land with a Piranha plant where as the concept art doesn't. It seems they plussed up some areas while they cut in others. I'm thinking based on the area underneath the castle is the main restaurant. The differences also may have thrown off my analysis of the land. This also leads me to believe there are some things they are very much keeping some things hush. It wouldn't make a lot of sense for Japan to have only two ride attractions and a bunch of stores considering their attendance is larger than Orlando which means capacity is a must. At the same time, they could be pulling a Potter with this land and increasing the number of stores, food, events, shows and increased theming to cover up one less attraction in the land.
I am now quite intrigued on what I'm missing currently as it could help answer some potential questions and ideas regarding whats going where and whats coming to Orlando.
edit: Of note, the entire Mario Kart ride was that huge indoor building. One thing both the concept art nor the teaser have shown us the full size of the Mario Kart building. Parkscope said the ride still has the same scope and scale which makes me suggest the size should remain around the same for the building...the scope of the airship and luigi on the plans were tiny free spaces within the mario kart layout. Japan's concept art and teaser still have three floors for SNW. Mario was on the ground level, Luigi second level, and Bowser third level.
Another item is look at the tracks for Mario Kart on the original plans. Two tracks become one track then closer to the end four tracks then back to two before coming into the station. There is also a Rest Room located inside the show building.