Considering that Ian was already working on them before 1.0, and never stopped until a solution was found, we know for certain they were planned by at least one person on the Go team. If you are struggling to say that Go people are not a single monolith then sure. Nobody has ever thought people are a single monolith.

However, the original announcement makes the intent of the project clear: "Not yet", not "never". They were always planned to be accepted into Go. But not before an acceptable solution was found.