"Yamato can't join because her introduction was so sudden and rushed and her motivations are so cookie-cutter and run of the mill, and her flashback is short and shit, and she doesn't have a defined role in the ship, and she's too much of an Oden wanker in an arc already full of it, and she's also an Ace wanker that wasn't needed at all after Tama, and she hasn't interacted with any Strawhat in a meaningful way and she's too strong, and the only thing she has succesfully done is stall Kaido for a few minutes and be a cheerleader and spectator for Momo, and her combat abilities are literally Kaido kanabo spamming 2.0 and she's a Mary Sue with yet another Mythical Zoan that has pending lore all written over it, and if she's the last crewmember that closes the crew she doesn't have any weight to her character..."
Gee, I WONDER why there is any doubt that a character introduced at the last second possible in an arc full of horrible pacing and picked and dropped subplots and whose treatment has been confusing and not satisfying and it feels like there are so many things missing is DEFINITELY joining the crew.
Why is it easier to accept that "no, she can't join because it will be shit considering all of these things" instead of "I guess Oda's ability to handle characters in a meaningful way since the timeskip has been severely lacking".
It will happen and people will still deny it even when Oda addresses all the stuff about Yamato joining in half a chapter or something, just like he did with the so long-awaited Kaido's characterization and motivations.
Please, accept that Wano has been horseshit, Yamato is joining, move on.