Board Thread:Spoilers!/@comment-2153169-20160901162450/@comment-24674051-20160913165701

I think that they had planned on having Zelena back as well. and actually I think that the original plan probably called for the Marian ruse to be dropped early in season 4, In fact, the EP's said that they actually had an alternate ending to the Season 3 finale in mind, and changed it at the last minute to the Elsa reveal. I don't think they ever said what the original alternate ending was.

My head canon on that is that we would have seen some hint that Marian was in fact Zelena in disguise. Either that, or we would have seen Zelena emerge from the time portal after everyone else had left.

Point being that the Frozen Arc, and the eagerness of the writers to incorporate Elsa and company, threw off some of the planned storylines.