Small nitpick: Google isn't using Rust for the Fuchsia kernel. The kernel, Zircon, is written entirely in C and is based on Little Kernel. Google is using Rust for some userspace drivers (Fuchsia being a micro-kernel).
No, it's written in C++[1]. They're very different languages.
That said, Google seems to think C++ has something to offer to all kinds of development. It seems to work for them, but they are a heavily C++ shop. I wouldn't read too much out of their use of C++ anywhere; it'd be more surprising and interesting to see them use anything else.
Oh that's interesting. Zircon is based on LK[0] which is in C, which is why I thought it was still written in C. I wonder how much is left of the original LK code then.
