I think that the biggest risk of disappointment for Star Wars Galaxy's Edge are definitely capacity, the possibility of technical issues (Test Track opened something like 18 months late), and operational issues. All of these could leave a bad taste in people's mouth.
I am also worried that merchandise may be less successful than Disney is anticipating, which may make revenues less than expected. It is my understanding that the shops inside the land will only have thematically appropriate stuff. But is that going to be what people want to buy?
The good thing about the world of Harry Potter is that the stuff people buy consists of clothes, wands, and appealing food. Does the world of Star Wars have that?
@larryz
That said it's hard to imagine today's Disney building a new theme park in Florida. They seem so risk-averse, always trying to hedge their bets. I suppose from a short-term business perspective it makes sense, since they will spend millions marketing the new "land" and will essentially generate the same amount of demand a Star Wars park would generate (or at least close to it).
So in essence, with all the hype they will get a good chunk of the income of a Star Wars park without having to outlay all that enormous cost. Everyone wins except for the guests, who will be standing in line for hours just to catch a glimpse of the new land.
I would like to push back on this comment. I definitely see where you are coming from--Star Wars has a rich backstory and the kinds of detail that can work really well in a theme park. And given an unlimited budget, a whole day's worth of attractions could be fairly easily imagined.
But I actually think that the guests will win from Star Wars being in an existing park instead of a 5th gate. The reason for this is simple: infrastructure. When Animal Kingdom was built in 1998, it cost about $600-$800 million. A fair percentage of that cost was infrastructure: massive civil engineering efforts to drain and grade the site; physical plant such as chiller plants, parkwide maintenance facilities, etc; cast member infrastructure like costuming, cast services, crew member cafeterias, management offices; and transportation infrastructure like highway connections, bridges, parking lots, buses and other transit infrastructure.
I would guess that this type of infrastructure accounted for about one third of the cost of the park. In the case of Animal Kingdom, the animal facilities may have been another third of the cost, leaving only $200-270 million for rides and attractions.
When Animal Kingdom opened, it increased the attendance of Walt Disney World, but a lot of the new park's attendance was cannibalized from Epcot and Disney-MGM Studios.
Imagine what those parks would be like today if that $600-800 million was spent on new rides at Epcot and Disney-MGM Studios instead? I mean, Animal Kingdom is a nice park that a lot of people really like, but even it's biggest fans wouldn't have called it a whole day park for its first 19 years of existence. In the meantime, Epcot and the Studios stagnated.
So I guess my point is, if Disney wants to spend $1 billion on Star Wars in Florida, it could buy two rides, a ton of rockwork, and about half of the infrastructure needed for a new park. Or Disney could build a new theme park and loose almost $300 million on infrastructure that doesn't go toward guest experience. Do you cut rockwork? A ride? Or cancel other resort expansions? Would that be better for the guest experience?
I am glad that Disney chose to put Star Wars in the Studio park where it is somewhat thematically appropriate and where new ride capacity is desperately needed. (Personally, I think that after everything currently under construction opens, The Studios will still need two or three additional rides.)