Having said that Rob Pike told me that Go is now one of Google's "official languages".
... which just means developers at Go now have permission to use it, along with Python, Java, and C++, to build things, right?
I believe so.
Pretty much.
what does "just" mean?
What are your company's official languages used for?
Not so much permission as support. Being an official language means that the core internal libraries have Go bindings.
It is a standard language at google. It gets used for things like the download service and other high throughput service which is it's sweet spot. The TensorFlow project in previous iterations predates Go's official stamp of aproval at Google I believe and stopping to rewrite is an unnecessary step. It's possible that now something like Go would be used instead.