"The solution was ... a dynamic, real-time, photo-real background played back on a massive LED video wall and ceiling ... rendered with correct camera positional data." Gee, that sounds a lot like a holodeck. We've come a long way from using Wii Sensor Bars[0] for position tracking. [0] https://www.youtube.com/watch?v=LC_KKxAuLQw
For the VFX industry, the tracking had already been solved for ages, with those reflective little balls on suits etc. in a mocap system. The Wii sensor bar's thing was that it was really cheap. But yes, damn close to a holodeck. But you can't see depth in this setup, right?
And that's certainly not the goal with this. Something along those lines has been around for a while (https://en.wikipedia.org/wiki/Cave_automatic_virtual_environ...). This system seems specifically targeted for solving challenges for film production, as it probably should be.
I am pretty impressed that real time rendering has gotten good enough to use for these purposes. I certainly wouldn't have expected that those backgrounds in the show were coming out of a video game engine.