Yes WoW does have expansions that can make some older content irrelevant but it's no where near like Destiny. Every piece of new DLC in Destiny immediately makes much of the old content irrelevant. The new DLC is so little in content that it's hard to keep going months on end. It even cuts you off from things like nightfall because of a level difference. If Destiny offered more content in each DLC there would be no problem. Only reason why people even wanted Yr 1 guns is because Bungie hasn't really made anything better. Every new set of guns added on are mediocre except like 3 or 4. People liked Fatebringer, not because of looks, but because it was a good all around gun for PvE. New guns just don't have the kick old weapons had and every gun feels the same.