One of the things Rich talks about in this talk is semantic versioning is fundamentally broken. In fact any versioning scheme that allows removal is broken. In some sense this model encourages Rich's ideas better - since you can't version directly, you either make a new library or maintain backwards compatibility.

Of course the current 'go get' model has a lot of downsides, e.g. Non deterministic builds. I still think it's worth considering building on, rather than trying to fix semver. All that's really missing is a stable monotonic identifier - something as simple as git tree height may be enough.