Rumple couldn’t return without something drastic happening. There had to be a consequence. I guess in storytelling as well as in magic, there’s always a price. And they had to bring Rumple back.
This is what made me ok with it there had to be a price and if anyone was gonna pay that price it had to be Bae or Belle. Bae took his father’s example of sacrifice and died a hero, because of him they can save the town and with Rumple’s help they may find a way to bring back Henry’s memories.