As we know, Sanji is part of Germa Kingdom and part of Vinsmoke Family.
And we see in the last chapter of One Piece (One Piece chapter 988), he already confront with King The Wildfire.
Now the question is, will King vs Sanji continue? It could be.
But i have an argument why their fight should continue until one of them wins.
Sanji already using raid suit, and he still named his raid suit O-soba mask,
but he still doesnt accept his real raid suit name which is Germa 66's "Stealth Black".
Now, lets begin why Sanji will shout/reveal his real name "
Vinsmoke Sanji" in front of crowd or in front of King like Momo did.
Lets remind you why Sanji dont want to accept Germa and Vinsmoke as his real name
"Sanji dont want to accept Germa and Vinsmoke because of Judge, and his male siblings (Ichiji, Niji, Yonji)"
This is why Sanji is still dont think calm, he still doesn't remember if he had another important person in his family.
"Yes, its 2 female/woman in his family which is her mother, Vinsmoke Sora and his sister, Vinsmoke Reiju."
So for me, i think the fight Sanji vs King will keep continue and of course
King will had the upper hand and when Sanji about to get a final blow by King.
King will ask Sanji real name, and he will said "Vinsmoke Sanji" because he remember his mother, Sora and his sister, Reiju
And this is my headcanon will came, we might see another Sanji powerups other than Raid Suit.
What is that? Im not sure, but there is a foreshadowing why King have a wings.
Since Sanji attack/portrayal based by Diable or Demon, so its very possible he will have Demon/Lucifer Appearance with wings