Yes, someone important needs to die, I honestly don't see One Piece ending on the note that Ace is the only person Luffy THE PIRATE KING lost. Of course Shanks is also on the "potentially dying" list, but he can't be the only one.
But softening the blow is exactly what he loves doing, that's why I think there is a fair shot of Jinbore dying. We already talked about this elsewhere, but it's Oda's trademark: Whitebeard and Roger were already dying so it was fine that they were killed, Ace isn't Luffy's only brother etc. And I understand this, it's hard to kill such loveable characters like our heroes
Anyway, that's just my take on it obviously.