Well, this was a surprise!
I saw this morning on Reddit that Kubo had answered a question regarding Ichigo's final (and current) version of Zangetsu, which has been a topic of contention for many since the manga ended.
I tried to piece it together as best I could, but really this is only my interpretation of what's actually being said here. Feel free to let me know if I'm off the mark here, but what we've been given is interesting for sure.
Enjoy!