also, I should also mention this little detail that I didn´t get while reading it for the first time but I find this image really remarkable: >>/5025/
Ocellus transformed into the four main characters (Dolores, Trixie, Discord and Thorax) that took over the hive, saved the mane 6+ the princesses from Chrysalis and lead the changelings to a new era: To Where and Back Again. Considering that she said in the end that she exposed "her" story, it doesn´t seem strange at all that she studied the past of her species, let alone if she had an actual identity before getting the butterfly body.
Twilight appears there as well and I suppose that´s because she was the one who had approved Spike´s decision at accepting Thorax before the S6´s finale occurred.