Board Thread:General Discussion/@comment-1916997-20151203160229/@comment-25926288-20151203160918

Mostly likely one is Rumple's mother. All others have a low likelihood of appearing, close to none.

Reasoning: Rumple's mom was a red herring casting, but it could mean they are interested in showing it. Probably not, though. David will never get any reasonable focus and I don't blame them. Hook's mom is fairly irrelevant to a host of things, but is the second most likely. Robin will get anti-focus. That's how much they care.