The tooling, configs, etc are all open source [1] (and largely run on Kubernetes!), but the actual deployments have been Google operated. This is about opening up access to operation of the deployments. I'm not about to stop working on the automation etc. :-)
[1] https://github.com/kubernetes/test-infra
Edit: if anyone is interested in more, we have a post out on the Kubernetes blog today about some of the infrastructure: https://kubernetes.io/blog/2018/08/29/the-machines-can-do-th...