As of now the only missions I can think of that dont have nodes are the first mission in the base game, the 4th mission in TDB(its locked behind all the urn challenges and i think the mission itself is called urn of sacrifice too), and the Skoriks mission(which was just made playable through a bounty today so there may be other similar ones later)
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with the removal of queens wrath bounties, the skoriks mission is unplayable. Why design a mission with a boss only to scrap it completely from the game? it makes a lot more sense to just give them a node instead, more content is always better in this situation.