User blog comment:Xilinoc/Ch. 684 - The Blade/@comment-28131457-20160728135642/@comment-24769684-20160729224844

Also, another thing that got affected is that Kubo was definitely aiming for a final slew of main character covers before the end. So there were likely going to be at least 4 or 5 more volumes' worth of content, but now we're cut off at Renji. Which does at least make SOME sense in regards to how Kubo could only have those three battling Yhwach. Who knows, an Aizen cover might have gotten thrown in as well.