Blackbeard is the new whitebeard and the new xebec
Kid, law, shiryu, ect. cannot be the new whitebeard. The principle thing that put WB apart from the rest of the yonko was his devil fruit. Yeah he had ACoC, but so does every top tier CoC user.
Shanks's mastery of ACoC was seemingly on par with WB's. So what put WB over? What gave him the power to destroy the world? The gura gura no mi. And only one person has that DF at the moment.