The Crow I think will eventually become the new hunter vanguard since he seems to be trying to help organize the hunters more after season of the haunted. Plus Cayde said that anyone who kills him gets his stuff including the rank of hunter vanguard. As for the speaker, his job was to speak for the traveler and was qualified since the traveler communicated to him through dreams (which is confirmed in the constellations lore book so the whole “I never said it spoke to me” thing in the red war was probably just him screwing with Ghaul ) but his job was to speak for the traveler while it was dormant, and now since the traveler is awake there ain’t much need for a speaker.