I think the game changer is he turns Bae 14 again then takes Bae with him to Neverland so he never has to grow up.
For ep21, MRJ tweeted about filming at the beach, and I wondered if that may be a Neverland location, because SB isn't known for its beaches. If so, that would mean that adult Bae goes back to Neverland.
Possible. But there could be many other locations that beach was for. It could even be a flashback of Neal and Emma when they were together. Probably unlikely, but still possible.