Yeah, I don't really see an argument against this tbh. Way back in like chapter 5 or whatever, Luffy even made it clear that the king of pirates would need the WSS under him, implying Zoro will have the title when the crew reaches Laughtale, or at least around that time,which generally makes more sense story wise, and with the Warlord system ending, Mihawk isn't affiliated with the government anymore.
Regardless, Shanks is going down before Mihawk anyway.