Of the people in the examples in the link, only person #1 is structurally unemployed.
Structural unemployment is a kind of unemployment that occurs when the skills that a person has are no longer needed in the economy. This often happens when, as in the case of person #1, machinery is invented that can do the job once done by a person. Structural unemployment also occurs when certain types of products are no longer demanded by consumers. For example, many people who played brass instruments would have lost their jobs as big band music lost popularity and rock music became popular.