Chapter 631 shows Crocus and Laboon for the first time after the timeskip. Crocus is drinking with an unknown person wearing a Samurai or Japanese clothes which it seems related to Wano Kingdom.
When this chapter came out, we all knew that this was foreshadowing for the events of Wano. After all, this arc was hyped up since Thriller Bark and we expected it to be heavy in reveals.
So far, it has been, but there is still one big mystery to uncover, who was this man casually drinking with Crocus? Since we know that the old man was the doctor of the Oro Jackson, seeing him being so friendly with someone clearly led us to believe that this man was part of Roger’s crew.
So a lot of people assumed he was Gaban and that we would meet him in Wano. But the third and final act of the Wano Arc is now running and Scopper Gabban as yet to appear. This would be weird to include him this late.
Another theory was Shiki the Golden Lion, due to the similar coat and haircut but I don’t see why Crocus would be so friendly with one of his captain’s former enemy (and not a friendly rival like Whitebeard, a true sworn enemy) and from what we know, the Golden Lion has no ties whatsoever with Wano Kuni.