Wish realm is the only thing that makes sense. There’s no way that SB Hook or Rumple would suddenly not care about Emma or Belle and the show wouldn’t want to keep calling attention to the fact that JMo and EdR aren’t there with the whole “where’s Belle?” and “Why isn’t Emma with you?” questions.
WR Hook doesn’t know Emma romantically and WR Belle is already dead so WR Rumple isn’t going to be searching for her. The only spanner in the works would be Regina. I have no clue how they’re going to do it.