You've just hit on the difference between a programming interface and an implementation of that interface. While the specific details of a site's design may change over time, there are certain characteristics inherent to the data that should always exist. A well-designed solution for scraping news articles would have some sort of API that defines common attributes of all articles, and a set of site-specific implementations of this API. If a single site changes its structure, then just change the implementation while keeping the API consistent.

For example, smalhotra discusses "title, publisher, date, author, byline, content, category, related articles, related links, imbedded images" as being general classes of information, that a news article could have.