Yeah, let's be real -- just as with Go Modules and the "try" proposal, there is no "open source process" when it comes to major language changes; the decision is always ultimately made by the core team, not the community. And I agree with you -- this arrangement is fine! I strongly prefer it that way. The Go devs have an excellent track record of getting it right, even when it went against the prevailing wisdom.
Personally, I'm opposed to adding generics, but if we have to...I trust the Go devs to do it better than just about anyone else.
I don't actually think that's a bad thing: I love it that Google pays people to work on Go full time, and don't mind the language being spear-headed by a tight team with a vision (who happen to work at a commercial entity). I'm impressed with their direction, and ability to say no.