Mihawk really has no place to fight Zoro now, or really only one condition - after everything ib OP is done, or he earlier WSS, Luffy as thr PK needs to have his right hand man as the WSS.
The problem is there's no tension to Zoro vs Mihawk, it's now a fight to surpass his master, while no problem with that how does a fight like that take place in possible scenarios like:
OP is found, Straw hats vs BBP, void century info, world turned upside down, fight against the WG, meanwhile in the middle of all that Zoro fights to surpass his master.