It's not always a blessing when your pairing have ended up together in some way, because that brings more restrictions on what they can do in fic. We end up all knowing what happened and when so we can't just make it up. While I enjoy the occasional ability to go "Squeeee, my ship is so canon!" it tends to get old for me pretty fast once I realise there's only so much I can make up before I have to start labelling things as an obvious AU.