Regarding the "point" made in the first edit, yeah you're not taking in the whole picture. This new prison of elders activity is only going to be a 3 player activity. That cuts raid teams in half and no one is happy. Bungie lead everyone to believe there was a new raid coming, there is no disputing that. They intentionally waited to push it back so that people would buy this expansion, and to use it as more incentive for people to buy future paid dlc. This reasoning is not entirely confirmed, but that's what they have gone and done either way.