Can't see that happening man.
If Zoro vs Mihawk doesn't happen, it's not going to be because Zoro will fight a variation of Mihawk that doesn't share any history with him, it's going to be because some villain defeated Mihawk and Zoro will both have to avenge his mentor and fight someone different for the title of WSS.(like Shiryu for example).
It would be extremely weird if Oda threw out all of Zoro's history with Mihawk, to instead have him fight..... Another Mihawk lol.
Would be odd thematically
mihawk is never really going to look like a villain up against zoro
have to think 2 years of training in close proximity everyday would have left its mark .
that I think is the most critical block.
its hard to imagine an arc where he plays the role as an antagonist . Not so much for his clone whose potential might be even stronger than he is.
just spitballing tho , i think it might be oda's way of giving fans a mihawk zoro fight in a way that still fits the role his previous enemies played in the past. otherwise, I imagine an epilogue type format where everything is done and they duke it out for the title with no other stakes attached.