The article author points out, correctly, that Go code has far too much "interface{}" in it. That's an indication of real need for more power in the type system.
Generics may be overkill. Parameterized types may be enough. The difference is that you have to explicitly instantiate a parameterized type. Generic functions and classes get instantiated implicitly when used, which gets complicated. (See C++'s Boost.)
Go already has built-in parameterized types - "map" and "chan". Those are instantiated with "make", as with
p := make(map[string]int)
That's an instantiation of a parameterized type in Go. Go already has a full parameterized type mechanism. It's just that users can't define new parameterized types - all you get are "chan" and "map".
For parameterized types, struct definitions would need type parameters. A parameterized type would later be instantiated explicitly in a type declaration, with the parameters filled in and a new name given to the generated type. This is more explicit and less automatic than generics. There's no automatic specialization, as in C++.
This is enough that you can write, say, a binary tree library once and use it for multiple purposes. It's not enough to write C++'s Boost. That seems in keeping with the design of Go.