Was this necessary? No. Did I like it? Yes. It is just nice to get a little back story. Enlightening to get to know more about why Cinder is the way she is. This little read will support your love for Iko and Peony and of course back up your hatred for Adri.
If you some time to waste at the dentist office or are waiting to pick up your brother, this would be a fun, quick way to waste a few minutes.