Closure, Limited is a book of stories set in the same universe as World War Z. That's the only connection. The style, characters, locations, etc, don't need to relate to each other.
Examples: Fear the Walking Dead is set in the same universe as The Walking Dead, but there are no plans for the characters to ever meet. Nor is there any reason to use the same locations, style, etc, of the flagship show. AND, the TV show Fargo doesn't have much to do with the movie, and even season two is set in a different time period. They are just taking place in the same universe. Not necessarily direct sequels or prequels.
The title story may be the only one directly related to the events of the book World War Z. From Amazon:
Set in the same terrifying universe as his million-selling World War Z, Closure, Ltd is among the short stories found within this collection. In it, Max interviews the head of a company dedicated to finding emotional closure for survivors of the zombie war by assassinating their former zombie attackers. Written in his trademark style, these tales are a combination of horror, drama, and socio-political commentary.