Eh im fine, he dropped the title so Luffy could say it
His personality his own clearly not forced. His dynamic with rayleigh is not like sanjis with zoros either.
I cant prove this, but after the Sanji-Robin-Black Maria, and Kizaru on Egghead debacle, where in both instances Oda needed to post-chapter/volume needed to clarify, i think oda,
RIGHTLY SO, has lost all trust in the general audience reading the manga so he needs to elaborate this stuff now cause he legit thinks the reactionary audience is too dumb to read

It is sad but it is what it is, i fully believe this