Yep! I have to say that it gives me Sim City 4 vibes, what with the music and the flying over a city's infrastructure, haha (Believe it or not, Sim City 4 has an awesome soundtrack that also does the "human voices = humanity's struggles and progress" thing, which I think Sawano is also evoking with the vocals.) I don't have experience viewing works that include his music, but from what I've understood, in general, when musicians sample or use vocals from different languages, it's to create a "sound of humanity," almost like the sound of world music. Considering these are some of the last survivors of Earth, and the importance of technology in their survival, the digital sounds combined with the vocals should be like a symbol of that struggle of humanity and the necessity of technology for progress. But it's also good to have ambient tracks too
That's why I think it's fruitless to try and understand some of the "engrish" though, since the goal might not necessarily be to create a fluent message, but rather, to have just enough of a sound from a certain language in order for the human voice to evoke that humanity.