My thoughts on the delayed raid: Crota's End was designed to be a gauntlet of combat: one harrowing near death encounter after another. Two things went wrong: the map layout allowed for easy cheesing to skip fights (the lamps and bridge), and ghorn wrecked (rekt if you prefer) the two most difficult challenges of the raid, kill the Deathsinger, and bring down Crota's shield. Bungie did not foresee that, and because of that, they probably had to redesign the Trials of Osiris with ghorn and cheesing in mind to craft a better raiding experience. Raiding is the high point of Destiny, and they know we deserve a better raid; so they're going to give it to us. Just...later.