If the $10k tickets provide a private area separated from the other passengers with a partition that prevents observation then I'd expect privacy from being recorded. Likewise in a hotel room, it's a solitary space separate from others and I'd expect privacy from being recorded or observed by employees entering my room. I'd share your same outrage!

However my experience stems from two long haul flights in economy and a handful of domestic flights in the same class. If someone was recording me while I was sleeping there I'd treat it the same as if I was napping under a tree in a national park. I wouldn't be concerned.

If there aren't measures in place to prevent other members of the public from observing then I expect recording is a possibility.