I can't speak for the GP, but there are plenty of jobs that expects you to euphemise items on your CV. At many consulting shops you will be violating your NDA if you name clients, but there are also many places that simply value discretion without legally requiring it.
Yeah, this is the exact right answer. The artists in the crew have the pieces in their portfolio. The techs are free to go into details when needed. For much else of the gig and things around it go discretion is the norm.
Well, it's all public now, through various straight forward means like this article, public postings on the website by the owner, etc. This covers most of my NDA. At the time, most of the secrecy was for game mechanics. That's pretty moot now as well. I've had several jobs where nobody wants the specifics discussed, so I've gotten good at saying "Imagine if you had a shipping container with a lock that needed to open for a hundred different people at a hundred different times". You can zoom into and out of problems with fabricated scenarios.
The other side of this, is that for the 18 odd months that Book One was open I would just give you a card. From my POV, that was better than any description I could give. I gave them out like candy and I still only had about 50 or 70 people come through. I probably gave out a hundred and fifty invitations.