That's a very cool character trait but sadly not every cool stuff or strong will thing relates to the disposition to become a conqueror.
Personally, it might seem like a biased opinion, but I believe he has atleast a 50 percent chance of getting it, sanji is a great leader, people naturally follow his orders, he lead the g5, Nami chopper and brook considered him the captain when luffy and zoro weren't around, he made viola and pudding switch sides, he motivates usopp and vivi etc...
And it's not like there isn't any possible foreshadowing, at WCI when he was simping for nami she commented saying that there's a weird aura, then jimbei added " it doesn't seem like conqueror's haki" it just feels oddly specific, could be just a gag, but it's not the first time oda turned a sanji gag into an entire plotline