The problem is, there is a very simple way to address this and that is Shanks. We still do not know what Shanks intends to do in the EoS. Mihawk lost his title as a Shichibukai, so let's say hypothetically there is a big chance he and Shanks ally when it comes to the final war.
Doing this means that Mihawk has part of any potential future conflict with Luffy. It has nothing to do with there being animosity with Zoro or some detrimental thing that Zoro must stop Mihawk from doing as a villain. These 2 men simply want to fight and see who's stronger.
If that is done and it just so happens that Mihawk and Zoro fight because of it, then it does not matter. Mihawk is still an antagonist, just not a direct villain with villain problems.
Try and compare this heavy impact with Shiryu or Fujitora or anyone else. Its not just about the WSS title, Mihawk IS Zoro's dream. Everything he did to get stronger is because of his encounter with Mihawk at Baratie. Take that away and you remove the purpose of Zoro's dream completely. Nobody else in the series can replace that purpose.
And Shanks is still probably the most important character in the series bar Luffy and his crew, so to assume these 2 groups won't collide in the EoS is disingenuous to everything that has been set up by Luffy's dialogue or strange behavior.
Tldr: Wait and see what Shanks and Mihawk do next before putting all your eggs in one basket.