Hi there! Here by way of st_aurafina, and I very much agree with your take on these things.

I would be super sad if Mulan and Aurora were done with the show. I WANT MORE. And I want to see Mulan fleshed out more as a character.

It seems like they will stay on -- when more Storybrooke residents learn that their homeland still exists, they'll want to find a way to get back there. And having things that are actively happening on that side will make that effort more interesting.