Now I have mixed feelings about this rumor. That cover photo for the book you see looks nice but its just recycled artwork and could easily have been photo shopped by someone who just wants to troll us all. (Though I find that unlikely) I personally think this book will exist because some of the flyers need a bit of balancing. Also the Crusade of Fire campaign book had tons of special rules for flyers that can't be used in tournaments and other things because most people don't own the book. I want to get a pair of flyers just so I can have dogfights. Its like adding a special form of challenges but for flyers instead of Captain Ward of the Ultra-Mcnuggets.
All in all I think it will be a mostly useful "Compendium" and I will Definetly pick one up for review if/when it comes out.