its funny how you say that meeting every straw hat is a low bar that Yamato hasn't accomplished yet, well if it was a low bar to begin with then it probably wasn't all that important in the first place.
That's not how bars work, lol. It's a low bar because it's very easy to pass,
not because it's of little importance.
It's very easy to meet someone that can fight in the new world. That doesn't mean it isn't absolutely essential to be able to fight in order to join the crew at this stage.
Going by your logic, Sanji should have never joined the crew because he never talked to Zoro *before he joined
Except that he did though, lol. On numerous occasions. Including multiple very stand out moments in the arc. Go refresh your memory.
Jinbe's never talked to Zoro directly either. And in Wano, Jinbe still refers to Zoro in a formal way by his full name Roronoa Zoro. Why did Jinbe still join the crew?
Jinbe still joins since he's very familiar with the crew as a whole. He's known Luffy since before the timeskip, he fought alongside all the straw hats during the battle at fishman island and was in the big spread with them.
And then at WCI he further interacted with the group. As previously mentioned, recently when someone's about to join the crew, Oda tends to have them develop a more significant relationship with 1 or 2 existing members in particular other than Luffy.
Chopper had Nami and Sanji
Robin is an obvious exception with narrative reasoning
Franky had Robin and Usopp
Brook had Zoro and Franky
Jinbe had Nami and Sanji
They don't have to have a specific interaction with each and every single member of the crew, but they need to be known and associated with enough of them that their integration into the family would feel natural. There's heaven and earth between how the crew knows Jinbe (even before he joined) and how the crew knows...or rather *doesn't know Yamao.
Your argument that: a potential straw hat must meet all of the straw hats and interact with them in order for them to join and its non-negotiable
My argument is that a potential straw hat needs to be friends with and familiar to the crew
as a whole. If they don't have a bond with one specific member, that's fine as long as they have interacted with and are known to the majority of the straw hats.
You can literally check this easy requirement off for each of them. And these panels are just one of many interactions multiple of them had with the crew.
You can read around the panels posted above too. It's multiple pages of just the future straw hat talking/interacting with the current straw hats. It always happens. It can even be an antagonistic interaction such as in the case with Robin. Nonetheless, Oda always makes sure to present them very early on to the crew and rapidly makes them a familiar face, not only to readers, but to the actual straw hats themselves.
There were many easy opportunities for Oda to do this with Yamao. As I said, she literally ran past the entire crew in order to get to the top of Onigashima. We've seen how frequently people move around and interact with one another in comedic ways such as Sanji, Zoro and Law recently, or Usopp, Nami and Tama. Oda completely skipped all of that with Yamao. Her only real interactions were with Momo and Shinobu despite all the straw hats being right there along her path.
Meeting most of the straw hats isn't only a extremely low bar, its also a inconsistent and inconsequential one.
Only if you're intentionally trying to ignore and downplay the importance of relationships and group dynamics within the main cast and a crew like the straw hats in order to make excuses for a total rando to rat her way in.