Based off of Moonie shorts [Filly Nightmare Moon], Chapter 95 Fate Conspires.

After watching the events of an alternate timeline where an adult Nightmare Moon was taking care of a child Anon, they get curious as to how that situation actually came to be. They watch and see how the alternate version of themselves first met. This also gets Trixie a bit curious as to how the version of them she knows met, and points out that they had promised to tell the story some time. And it seems this is that time.
As Trixie was about to throw Anon and Moonie out of her wagon, Anon convinces her to let them stay be agreeing to tell her the story. Though it's not much different from what she had seen in the alternate timeline, The story of how they met was still touching to her.

This is essentially my version of how the events in that alternate timeline would have happened in this timeline. Functionally, this acts as Chapter 95.5