Couldn’t this criticism be leveled at any walkthrough attraction? What could they do to alive you of those worries? I can’t think of any besides “trust us”.
I think you're right, that's an issue any walkthrough would face, but the difference here is that it's a permanent installation rather than seasonal. By the time other haunts start cutting staff, chances are they're gearing up to close anyway. I don't think we'll have a great idea on the future of Unleashed and how committed they are to maintaining staffing until we see how it looks in, say, January.
With the permanent location and fluctuating demand throughout the year, I was kind of expecting the mazes to be more effects/scenic heavy than they actually are; that scarecrow scene is awesome but the only real noticeable one I’ve seen so far. Instead the houses are more in line with the usual temporary installations; they seem scareactor-heavy which is a concern if they cut back on staff (Eternal Bloodlines from HHN33 is a great example of how terrible a house can be if you can’t keep it staffed, empty booholes galore).
Outside of the mazes is even more concerning; they weren’t really kidding about the warehouse feel. The bars and restaurants all feel like they have temporary overlays and leftover props rather than an actual space you’d want to explore. Based on those preview videos they’re relying heavily on actors to make up the atmosphere. If they get cut, that’s just a big empty box.
Usual caveats apply (it’s a preview so things change, I haven’t been there personally yet), but the more I see the less I understand the market for this. Peak demand is Halloween season, but instead of going to Vegas why not fly another hour to HHN Hollywood for a fresher experience than Exorcist: Believer for a comparable price? I don’t really think it has the IP strength to encourage off-season demand either, which again returns to are they going to cut staff during the slower times? Which hurts the quality of what they’ve already built.
A lot of the permanent attractions I’ve seen in tourist areas fall tend to be much smaller in scope; like the Ripley’s Haunted Adventures may be like 2-3 scareactors running an entire half-hour walkthrough. It’s a low overhead diversion that doesn’t take up the full night. Is there actually demand outside of Sept-Oct for people to commit their entire night to a premium haunt experience without a headliner draw (FNAF, Stranger Things, etc.?) I kind of doubt it, but let’s see how it goes.