Who are the most likely candidates to join the Straw Hat Pirates?
Stussy (She already betrayed CP0 and the World Government. As a result, the World Government most likely wants her dead and what better thing for her to do than join the Straw Hat Pirates?
Vivi
Carrot (Wanda should have been the new ruler of the Mink Tribe, not Carrot.)
Yamato
Out of all of these people? Stussy honestly. And even with her, right now her chances are pretty abysmal unless something drastic happens.
Vivi not going to egghead and instead being stuck with Wapol really hurt her chances for me. There's little to no indication she got any major power boost over the timeskip, joining an emperor's crew would be too dangerous. Plus she's considered the 5.5 strawhat.
Carrot is also done. Yes. Her ending definitely sucked and made no sense, whatsoever, however, her lack of any real involvement in Wano, her complete and utter defeat and getting cucked in her revenged match with Perospero was the deal breaker for me. That's just not how you'd write a strawhat.
Yamato: Red herring. The only purpose this character served was to sell merch and generate interest into the manga with nakama bait. The fact that people continue to cope with this reality is hilarious. Also she's just too strong.
The only chance she'd have at joining now is if someone literally built Momonosuke a hyperbolic time chamber xD. She is the guardian of Wano and that's not changing during the story's run.