Throughout One Piece, Oda has bestowed many titles upon Pirates, Supernovas/Worst Generation/Silver-Medalists/Yonko with the greatest of them all being Pirateking.
However there is another epithet that people barely ever mentions, because it is so rare and only TWO CHARACTERS have ever been associated to that title.
These two are
-Whitebeard in chapter 576 "The Great Pirate Edward Newgate", as he dies Oda chooses to refer to him not as a Yonko but as a Great Pirate, because his life as a Pirate is too overwhelmingly amazing for the chapter to simply be called "The Yonko Edward Newgate".
-Roger in CHAPTER 964, his title box says "The Great Pirate Gold Roger", this is Roger as he first learns about Oden being on WB's crew, Roger before he became PK was a GREAT PIRATE, which further proves this title is SUPERIOR to that of a Yonko.
TL:DR Luffy will never be a Yonko, he will jumps straight up to the superior rank : GREAT PIRATE and then becomes PK from there
However there is another epithet that people barely ever mentions, because it is so rare and only TWO CHARACTERS have ever been associated to that title.
These two are
-Whitebeard in chapter 576 "The Great Pirate Edward Newgate", as he dies Oda chooses to refer to him not as a Yonko but as a Great Pirate, because his life as a Pirate is too overwhelmingly amazing for the chapter to simply be called "The Yonko Edward Newgate".
-Roger in CHAPTER 964, his title box says "The Great Pirate Gold Roger", this is Roger as he first learns about Oden being on WB's crew, Roger before he became PK was a GREAT PIRATE, which further proves this title is SUPERIOR to that of a Yonko.
TL:DR Luffy will never be a Yonko, he will jumps straight up to the superior rank : GREAT PIRATE and then becomes PK from there