Some fans are saying this was supposed to release on Zoro's birthday, but it got delayed because of the unplanned break 3 weeks ago.
I don't really buy it, but I've wanted to see Zoro have an emotionally charged fight for 10 years. He's gotten rare emotional stakes with Tama, Orochi, and now Kiku.
King's haki awakening and Ashura awakening aren't out of the question in this arc.