Except that Blaze/Bazel share code, are very similar and converging over time. The plan is for Google to use Bazel+extensions at some point in the future. Borg and Kubernetes don't share code (they are written in different languages: C++ and Go), look similar only from a very high level perspective and are diverging over time.

Right. It's better to say that kubernetes was designed by people who were heavily influenced by borg.