I think you guys are barking up the wrong tree here.
If you look at the flow from point A to point B, it is not smooth. That tells me that Kubo has deviated in some form or fashion from his original story. Maybe it was supposed to end after the Aizen-Ichigo fight. I mean seriously, that would have been a decent way of ending this manga IMO. To a certain degree, there was closure.
Now in extending the manga (ignoring the Fullbringer arc), the story is not fluid anymore. We know there are still players that haven't been shown (i.e. Kisuke and Isshin), backstories (i.e. Isshin, the Quincies, the relationship between Yama and Juha Bach), as well as the avoidance of characters (i.e. Mayuri).
We've been told that some old characters will be shown again (still waiting on Grimmjow). We've been told we're going to see the strongest shinigami squad, the Zero squad.
And for you guys saying how could Juha Bach not have been noticed by SS? There's Yoruichi, Kisuke, Isshin, Ishida (both Uryuu and Ryuken), Ginjo, the Vizards.... need I continue?
It's not Kubo's strong point.