In the episode Manhattan, Rumple’s deal with Emma is specifically to get Neal to talk to him – this makes me think that Rumple and Neal had seen each other at least once before they were first separated. Possibly in Neverland.
I could see Bael/neal refusing to talk to Rumple when/if they met in Neverland. Rumple could be the reason that Bae/neal was able to escape Neverland.
Pretty sure Manhattan was intended to be the first time Rumple has seen his son in centuries. He wouldn’t need to build this curse to end all curses if he’d found Bae in Neverland.
I wouldn’t rule out the other way around, though, since Neal said he has seen what Rumple did to people who breaks deals.