Summary: Now that we know the background of the silos, we return to a different perspective, the instigators.
One of the unique perspectives that Hugh Howey brings with this extended series is a way of writing a series that does not primarily rely on affiliation with the main character to move the story. Instead while there are recurring characters in the books, mostly each new book has a new main character.
Done poorly this will mean that the author has to reacquaint you with the story and draw you into the character that you are now reading (and waste a lot of time for the reader in repetition). But with the Wool/Silo series Howey has used this method to move through a lot of time and tell the story from a wide variety of perspectives.