The fact that bungie has given out The Fate of All Fools proves that content was in fact cut from this game before launch. During the beta the code for Fate of All fools and all its stats and a bounty for unlocking it were all data mined and posted online. It was clearly ready to be in the game at launch but bungie chose not to include it in the game until now. It was clearly cut with plans to be added later on as part of DLC. If it was cut for any other reason (eg balance, quality, etc) they wouldn't have given out in game