It does not. It simply discusses ways of adding headers to arbitrary source code. The intention is to add license and copyright headers, but the reality is that these headers can say anything. It is discussing generic techniques for doing this.
It is advice for how to add headers to source files, not legal advice. This is a generic concept and the headers could literally say anything. They just happen to be license and copyright notices, since that is what he needs them to be. It is easier than opening each file in a text editor to manually add the header.
