I don't think Zoro is going to be fight another yonko level opponent until Mihawk. He either shows Ashura here or he doesn't and Oda wrote it out of the story (which i see zero reason for him to do).
I want to see Zoro use his other "demonic" moves like enbima yonezu onigiri and gyuki yuzume in this fight as well, would be interesting to see how Oda portrays those moves now since Haki is a lot more fleshed out.