Board Thread:Show-Related Questions and Answers/@comment-6036560-20131108000642/@comment-2157876-20131110215533

Don't worry even if they don't finish the story, writers will manage to give a closure in OUAT, but they have said that won't be necessary, this season will wrap up in the season finale.

Besides I believe that if the show is not renewed these characters will return or will have a cameo in OUAT anyways.