Interesting hire. As a startup it seems an unlikely one, Neal is a wonderful author, and has a sharp wit, but as he explains "his brain is not useful" to the work at hand. I could see consulting with him, but hiring him struck me as odd. In terms of what Magic Leap purportedly does my guess would be that Daniel Suarez (Daemon, Freedom) might be a better choice in terms of a vision that applies somewhat directly.
Well, they've got to do something with that half billion dollars. Decisions that don't objectively make sense somehow become possible when you've got that kind of money to spend.
Sad as it is, that is a very real danger of the 'over raise'. Way too many startups have negotiated their bankruptcy in their own, soon to be someone elses, overly well appointed offices. I picked up an Aeron office chair for $12 that way, very sad.