Not really what I expected. In all honesty, I've been reading these books for 7 years now, and I don't remember ALL the minor characters that have been included. Some disappeared after one book. I think that makes this coda unnecessary because there were too many characters included that I simply did not remember.
I think Ms. Harris felt that a lot of people were "disappointed" in the final book, and maybe did this to make those particular fans happy. It wasn't really necessary.