I think you unlock the raid at level 24 and that means every level 24 is free to attempt the vault with anyone who is willing to do it with them. And that's a good thing it promotes trial and error, but if there was matchmaking every stinking level 24 25 and 26 would flood it looking for a higher level team to get them through it. Since I assume the raid matchmaking would be like strike matchmaking you can't kick people so that people wouldn't just join a match kick the weakest links and invite their friend Jim. If bungie can find a way around this I friken salute bungie for knowing how to update a unfinished game.