I know this is gonna super suck if this is true ...but having beaten crota I am saying that once the hard mode releases your going to have to fight them before you damage crota kinda like stage 2 in vault of glass had detain during Templar fight and then detain for atheon and crotas end has swordbearers on stage 2 the bridge fight..so it makes since that crota will have swordbearers on hard