So, basically it was an analysis of how "guns" in One Piece are USUALLY associated with negative presentations: fire squad almost executing Zoro, Arlong killing Bellemere, Oden, Corazon, even Whitebeard being "finished" with a barrage of pistols from the BBP.
And also how Oda separates "humans" from "monsters" by also using guns. How Kaido and BM are these natural born monsters who are invulnerable, but characters like Oden or WB can be "shot" normally.
In WCI, the BMP developed special bullets in order to pierce the "monstrous" Vinsmoke siblings and their exoskeletons. We even had the small exchange between Sanji and Niji, where Niji told Sanji would end up filled with bullets. It was a little thing to say that Sanji was "human" unlike them.
What happens in Onigashima when Sanji starts thinking he might become a "monster" like his brothers? He runs away and GETS SHOT by some random bozos. His expression is pissed and we have the moment later on with the geisha that I dont remember the name when we ACTUALLY thought Sanji had hit her.
Which is why Sanji starts wondering about what would become of him. Then he decides that, despite maybe being more "useful" as a heartless person that wouldn't mind hitting women and shredding any enemy in sight, keeping his humanity is more important.
It's nothing new. I just liked the guns/invulnerability things the analysis pointed out.