> I want to know why golang change the access method.
The name of the programming language is Go.
> Anyone who knows the isssue link, please reply me. Thanks a lot.
There's no proposal and there's no issue. It always worked like that.
You cannot initialize the field 'Name' of struct 'Value' because
struct 'Value' has no such field. The (essentially) syntactic sugar
that allows to access the inner field like in 'value.Name' is
specified to work in selectors, not in initializers:
https://golang.org/ref/spec#Selectors