Imagine how epic the ending would be. Luffy doing the same smile Roger did before he died and then started a new age by saying the exact lines. But, since I also don't want Luffy, or any of my favorite characters to die, we'll make that as an imaginary scenario by Shanks.
Akira Toriyama killed off his main character, Goku, even though he didn't want to. He was gonna make Goten the new main character, but because his fans refused the idea, he tried to get Goku back. If Oda does the same thing, then he'd be able to bring back Ace.