Go marks features as deprecated, though, both in source code and in the docs. For example, strings.Title() has been deprecated and instead the case package should be used. The backwards guarantee merely means that the feature won't be removed from the library in Go 1.x, but when you write new code you won't use it and the preferred way of doing the same is mentioned in the docs and version notes. I think it's good not to remove deprecated functions within the same major version.

Except Go certainly is never getting another major version, I am waiting for Go 1.10000.0, given how decisions are made on the ecosystem.

What's wrong with Go 2 with tools to automate migrations? Of course that limits the scale of possible changes, but moving methods between packages should be possible with this approach.

Community culture, most likely it will never happen as such.

Change doesn’t have to come at the pace of npm. Let’s be charitable, people. :)