No need to retcon the Pyro Lore. I doubt anyone is seriously tied to Pyro being in 4.0, only that a 2nd system will be released. Given what we know from CitCon and the current lore- what they showed is passable for the Leir system. Leir is also unclaimed, similar in size to Pyro, has less planets, and basically uninhabited, but the lore says it is resource rich and has life. Pyro is supposed to be completely dead and uninhabitable. Spend the effort and get Pyro right, however much time it takes, release their currently developed planets as Leir. Retconning Pyro will do more brand damage than backing out of releasing Pyro and releasing another system - Leir