No, you asked for what her setup was to join. I'm starting to think you don't read what question I'm answering along with what I say. I can quote my original paragraph if you don't believe me.
The Chapter 999 title uses the pronoun "kimi", which only Yamato uses, so yes she brewed it. When you then combine the titles, it's Yamato saying she brewed sake to drink with Luffy.
The only time Luffy does a sake toast with someone is when a new crewmate joins. Even if you look at when the grand fleet was created, they were toasting to another drink. Jinbe was going to be inducted through sake before it got delayed for no real reason. As everyone agrees here, that's most likely because a new SH will be there for it as well and the one with the most setup around that is Yamato. It also properly wraps up that plot thread with Ace never getting her to join his crew after the sake toast they shared.
I'll just leave this here again. Robin was accepted to join by Luffy simply cause she's a good person. They had a far less developed connection/relationship than he does with Yamato. Luffy never shown any starry eyes or interest the entire time before that and he still had no problem accepting her question.
When Yamato asks Luffy to join after the raid, what makes you think he'll say no?
Luffy is the next Roger due to their striking similarities in their personalities, actions, and desires. This was the case when Ace was alive as well so I really don't see your point here. Ace, Momo and Yamato all dealt with being in the shadow of their blood father they had nothing in common with and their arcs revolved around coming out of it. Ace, just like Yamato, took after his father's rival and Momo is becoming his own person while resembling Kaido's image. Saying Momo is the next Oden is inherently wrong with his entire character arc.
I asked for setup -> you responded -> I asked if Yamato was a Brewer per your response of setup -> response that clarifies the 999 title is Yamato's words per "kimi" therefore making Yamato a Brewer. I read and responded. You clearly understood what I meant as you answered. I admit this could be foreshadowing.
Every crewmate had a sake toast when they joined? I don't recall that.
I've already stated Luffy would not likely refuse Yamato a ride on Sunny. I don't think Luffy would refuse most people. Yamato asking to join is probably the same. Yamato's a good person who is strong. But my point is what else? Others have been good and strong but they aren't crewmates. And IMO Yamato self inviting as is is not a good setup compared to past crewmates. Luffy asked Vivi to join who refused but was a red herring to Robin self inviting after saving each other's lives not simply because Robin's a good person. Luffy and Robin's relationship developed based on those experiences. Then promptly after joining Robin won the crew (besides Zoro) over. Robin's Devil Fruit powers were what interested Luffy, Chopper, and Usopp sealing the deal. No starry eyes necessary to see Luffy was happy. Maybe Yamato DF powers could make snowmen or icemen as Luffy would love that (though why hasn't Brook done something like that). But I'll agree to disagree Yamato's relationship with Luffy as is is more developed than Robin's and Luffy's. Nothing Yamato has done in Luffy's POV tops Robin saving Luffy's life IMO.
Ace and Yamato don't like their biological fathers. Momo is different. I doubt Momo has problems emulating his father. In fact, Momo probably could do a better impersonation than Yamato now that he's grown.
Here's my problem. You are accusing me of brushing off your rebuttals yet refuse to acknowledge a possibility I mentioned. Yamato stays in Wano for Momo.
Similar age in 28
Similarities with one another's fathers
Both in line to be Shogun
Yamato can mentor Momo with powers
Developing bond
Mythical Devil Fruit users
History in Wano
"Rightful Heir" and "Enemy Princess"
The setup is there. It's deliberate by Oda.
There are a still questions unanswered that may go against Yamato riding the Sunny.
How do you think Yamato will act/respond if Momo looks similar to Oden? Yamato may be giving Pudding levels of personality disorder and Bartolomeo levels of Oden fanatic. Imagine...Yamato Kozuki. Marrying Momo who may look like Oden and having the Kozuki family name may be the closest for Yamato to being Oden Kozuki.
Why hasn't Luffy seen Yamato or any Minks transform? This is deliberate. The payoff may be huge.
What's stopping Yamato from changing their mind on when they leave Wano? Opening Wano's borders will mean an increase in border security to compensate for the the lose of security from closed borders. Yamato may feel guilt for their father ruining a great nation and take responsibility by helping protect and rebuild Wano. Leaving Wano happens afterwards.
Who would Oden consider his succesor is?
Luffy freed Yamato from her physical chains and Yamato protected Momo and Shinobu after Luffy asked her too. She also countered Ulti for him and held back Kaidou from hurting anyone else after he lost around 2. This is even putting aside they both did a side by side attack against Kaido at the start of Round 3, so I think there’s stuff they like about each other already.
Luffy didn't need Yamato's help against Ulti as he was about to turn Gear 4. Yamato showed they can follow orders and can fight. Luffy had a side by side attack with X Drake. Doesn't mean X Drake is joining.
What does Luffy like about Yamato?