I vote for the airlock.
BTW,
@Missing20K, I'm glad you're feeling better and I'll try to be nice and respectful in my response, even though it will be much less fun for you. Personally, I like the humor and ribbing I get from my friends when I ask a question they think is stupid. It's probably because it's not my first interaction with them, I guess. Anyway, here's why I think your question puts the board into an unreasonable position:
Are you really asking for serious specifics about what Disney intends to do when a guest is unhappy with the immersive experience for which they've paid $1000 a day? And are you specifically asking what techniques they will use for the perhaps 1 in 1000 (or less) people who are going to feel this way?
Personally, this isn't the most interesting aspect of this immense creative project that I could think of to discuss but since you seem interested in it I'm willing to help out:
1. BTW, I'm betting that you haven't read the exhaustive and exhausting previous 99 pages of this thread so you haven't noticed the 8 pages of posts discussing whether there would be bus transportation to the other parks. The consensus was that there would not be, though as with all of the discussions here there is a vocal minority that this would be a big mistake. But this minority also can't conceive of anyone wanting to spend 2 days participating in this glorified murder mystery weekend.
2. You've also missed the 20 pages discussing the ridiculous conjecture that Disney would confiscate all cellphones and other communication devices. The consensus was that they would not do this. There was a vocal minority who thought it was terrible that Disney would prevent doctors from engaging in lifesaving consultations while on vacation. I feel like doctors will be able to avoid breaking immersion and HIPAA and not discuss patient information in public.
3. I agree with the others who say that Disney isn't going to run scheduled bus service for the 1 in 1000 customers who wants to visit a park during their experience. I think they will let you call Uber or a Minnie Van for this. Defectors can probably afford the Minnie Van since you're already wasting your $1000 a day on this. Ha!
4. I think the customer service and satisfaction aspects of someone who is unhappy with their $1000 a day experience will trump any worries about breaking immersion, but I was actually semi-serious about the airlock solution. I'm sure that there will be a discreet airlock for you to exit through. Ideally, they wouldn't even need a traditional hotel lobby since there's not going to be constant check-in/check-out activity, though I could see a themed spaceport aspect going over well. This part would be "outside" the spaceship proper, though. You'd just exit through one of the airlocks so though you will break your immersion when you exit the airlock into the spaceport that you never left, someone remaining on the ship will just have to deal with the trauma of seeing someone enter the airlock without a spacesuit.
Actually, you'll have to revoke my Star Wars fan credentials, I've just discovered that they've even named this effect the "Stormtrooper Effect". The weirdest thing is that there are theories about how it reflects the realities of war where large groups of soldiers will consciously or subconsciously intentionally miss.