Are the Archon-Slayer and Urn of Sacrifice quests no longer available? I don't see them.

Is there any way to play their associated story missions, or are they gone for good?

Are the Archon-Slayer and Urn of Sacrifice quests no longer available? I don't see them.

Is there any way to play their associated story missions, or are they gone for good?

That's a great question, I might suggest posting it on the Bungie help forum because I doubt anyone here will know.