I think Zelena controls Rumpel’s use of magic. But she does not control his mind. Rumple actually hers. Let’s suppose Rumple ended up in Oz, with Zelena in control. Rumple is now worlds away from his family. No magic, no power. No way to be reunited.
Zelena. Why on earth would Zelena want to put everyone back in Storybrooke? What’s there for her that she didn’t find in Enchanted Forest, or in Oz. she could have destroyed Regina in EF if that was her goal. And why on earth would she put her curse in jeopardy by allowing Emma to return?
Rumple. Rumple would want everyone back in Storybrooke. Rumple would want to be as close to Belle and Bae as possible, and now he is. Rumple would want the savior to return, and she has. Everyone is in place for the curse to be rebroken, and for Rumple to be reunited with Bae and Belle. ( except for that pesky where’s Neal deal)
It would be really easy for Rumple to control Zelenas actions. “Why did you choose Regina over me?” “Ah because she is stronger willed than you are, Dearie. You could never have cast that curse. You couldn’t even recast it today through blood magic, because it requires Regina’s blood, and you could never get Regina’s blood.” “Ha! You think I can’t recast that curse? Watch me!”
And now, here they all are, back together in Storybrooke. Rumple now has to get Zelena to reveal to his family that he is indeed alive, and that he is with her. He knows they will find him.
“You should never have brought me back.” Ah, but isn’t he exactly where he wants to be?