I dont for a moment think that Rumple didnt make Cora pay a price for tricking him in their baby deal. I actually think since Cora broke thier second deal, that Rumple went back to thier original deal, which was Cora giving Rumple her first born in exchange for him teaching her to spin gold.
I could see him doing something like that. But I could also see that, if he already knew he was gonna corrupt Cora’s child, that would be revenge enough for him. And having Regina push Cora through to WL was some bonus punishment for her having gone back on their deal too. So I could see them maybe writing in another altercation between YoungCora and Rumple, which involved BabyRegina somehow. But if they just leave things as is, it doesn’t feel like there’s a hole in that aspect of the story for me.