I was not really convinced by that line of argumentation either.
For me, the more convincing argument is that Go would have probably happened in a parallel universe as well. Imagine that Griesemer, Pike, and Thompson had worked another company that gives the freedom to work on personal projects, it is very likely that they had come up with the same language. They have argued in talks that Go was created as an answer to problems that they identified in the development of infrastructure at Google. That may have been a trigger, but Go is firmly rooted in the tradition of C, UNIX, Plan 9, and Limbo and a logical next step in that tradition.
Hence, to me, Go is really Griesemer, Pike, Thompson, and Cox' language and not Google's language.
Of course, the title of the original article that Taylor is reacting to was a bit sensational. But I think the original point was that Go is not a language that is developed by the community, but a small set of people. Whether they are employed by Google, Facebook, Uber, or Zalando is somewhat irrelevant to this debate.