The worst thing is that eventually, github will start to want to monetise even more, and we'll see it turn into SourceForge, at which point many projects that have tied themselves into github rather than spreading out more carefully amongst other git hosts will face a bit of an existential crisis.
This is part of why I have some issue with the Golang packaging story, it pretty much requires you to refer to dependent packages as `host.com/user/pkg`, so in most cases it's `github.com/...`. You can manually rewrite this, but that's not really ideal.
In case whether 'search & replace' method is not an option you may create your own 'proxy' server like gopkg.in [1], since Golang packages don't have to be only on GitHub [2] you may set up mirroring rules to overcome problems with package location, version/revision, or library when GitHub downtime may occur. Personally, I don't think if creating own proxy server as solution would be quite big deal whether there are many various dependency tools for Go. 'Search & replace' is not mission impossible either. Go is not PHP - it just won't compile if (local) dependency is broken.
We'll never learn.