Yeah we kept our eyes out for whoever that next person could be so with any given name drop we went "maybe this is the one" but then as soon as we saw them (and in many cases the fact they were simply part of Kinemon's group") and how Oda handled their introduction, went "nope, this is not the one." and moved on two pages after they appeared.
Meanwhile Yamato had a ton going for him from the moment he appeared and a ton of us that have been saying "nope" for the last ten years to every character that shows up, are now going "this is the first one to feel like Oda's putting in that mileage."
We had to make a new thread in week two because the opinions on Yamato were so strong. It was a hell of an entrance (two memorable entrances in fact) and all the follow up since has made it stronger still.
All the plot ties he has, the personal connection to Luffy, the promises and questions already made that have to be dealt with, there was a ton there from the first chapter, even before he took the mask off. And he's continued to get that exposure since.
I wasn't 100% on the train at the very start because Nami-face, but that's not an issue anymore, especially in the color design. And the sheer amount of development and screentime?
Yamato has to see Franky out of the robot suit. Meet Sanji to answer his question, and the gender gags that follow. Yamato asked Luffy to ride his ship, and that has to be dealt with, even if its a no. Yamato is one of the only people that knows about Luffy's second dream and it made him cry. He made Ace's vivre card. He's been studying and dreaming about THIS crew since Ace died. He has explicit dreams, and the gender bend thing is unusual. He has to face off against his father and show off the already promised transformation that was teased over a dozen chapters ago now, set up WAY in advance.
And if Oda gives us a Kaidou flashback like he gave Big Mom, then Yamato is probably going to be tied up in that as well. There's just… a lot on this character's plate and its the sort of focus Oda hasn't heaped on any single character since Law, and Jinbe before that.