Oda would never change the Monster trio dynamic and since Sanji is number 3 and a wing he‘ll have to surpass Yamato. That means there are 2 options:
• Sanji will surpass acoc without having it
• Sanji will get it later
:cheers:
Or maybe the end of the Pirate King's wings has nothing to do with strength. Moreover, if it really had to do with strength, you should accept that Sanji will lose his Wing status if Yamato actually joins. Because I don't know if Sanji will surpass Yamato in the future, but of course he is behind now, in terms of strength.
Zoro and Sanji will always be Luffy's Wings, not because of their strength, but because of their importance to him.
What makes Zoro a wing of Luffy is not his strength, nor the AdCoC... It's because Zoro has a way of thinking and acting very similar to Luffy, so he understands his captain very well. Also, Zoro is more mature, which allows him to remain calm in critical situations and act as Vice Captain in those situations.
What makes Sanji a Wing of Luffy is how well he reads situations and acts accordingly. For example saving them from Croco, sabotaging Enel's Ark, closing the door of justice, rescuing Momo...
That is something that will never change, regardless of whether Yamato or Kaido joins. Zoro and Sanji will always be Luffy's wings.