I wonder, would Go be more suited for Android or Rust? Obviously Google would much prefer to use Go since they're developing it and could optimize it however they want for Android.

On the other hand, Rust seems higher performance and might be more suited for apps, but Google doesn't have much control over it. However they don't have control over Java either, and they could create a "fork" of Rust if needed, just like they did with Java/Dalvik.