If magic isn’t there then the dagger won’t control Rumple. So I think magic has to come with the new curse
Maybe the WWW takes a special interest in Snow and Charming second child, who will be even more powerful than Emma. Look at what A&E had to say when the question was posed to them in the LR11:
Would a second child of Snow (Ginnifer Goodwin) and Charming (Josh Dallas) have powers?
Kitsis: Can’t say.
The last time somebody took an interest in Snow’s and Charming’s offspring, Rumple used their hairs to bottle true love and made Emma the savior of the first curse. Maybe WWW is doing something similar with this new baby and Aurora/Philip’s new baby.
"That’s how you know you’ve really got a home. When you leave it, there’s this feeling that you can’t shake. You just miss it." Neal Cassidy