To be honest, I think this is possible.
I have great difficulty believing that Sanji would reach this level, I emphasize that for me Admirals and Yonkous are equivalent.
Aside from the fact that he's a straw hat, he doesn't have much relevance within the world of One Piece. He's not a supernova of the worst generation, the ones we know are responsible for great feats in history, like now, taking down two Yonkous.
These guys are where I put my chips if I have to bet on who's going to beat the admirals. Along with Luffy we have Kidd and Law getting the spotlight, leaving just one more admiral.
Some might think the last one is for Zoro, but I find it hard for him to get so much more prominence than Sanji. He has always fought stronger enemies, but not as strong as the difference between an admiral and a vice admiral.
I really don't know what to think, for now I'm 50/50