Okay straight up if we are still not getting Xebec's face, that man has to look identical to a character we already know and Oda is saving that reveal for later. Be it Dragon, Mihawk, Blackbeard or whatever other top tiers are left with unidentified pasts, Rocks looking like somebody we know can be the only reason why Oda would make this much of a mystery out of it.
This would have been the perfect point to drop the silhouette. Why reveal fucking GLORIA was on that crew but not show Xebec himself already huh? If he was the burn scar guy is no reason for Oda to not show us Xebec since we literally do not know what that guy looks like either. So if they were the same, why not reveal Xebec now and later show he just got bad scars from God Valley when burn scar guy shows up if they are indeed the same?
There has to be a reason Oda keeps drawing this reveal out despite being in the last Saga and revealing tons of other stuff already.