It has been posed many times, most often by myself tbh I wouldn't mind at all if that was how it happened, the only problem with that is it would mean we still don't get to se Yachiru fight . UNLESS When the Sternritter come back, they find Zaraki, try to finish him off, Yachiru tries to defend him, so we see her fight, but eventually gets beaten, THEN they merge and all hell breaks loose.
I still think given her size, and her Reiatsu being shaped like a kittie, it would be AWESOME if Yachiru's release turned her into a cat , think along the lines of Pantera, but smaller and more awesome
You have a point Also I expect to see the Royal Guard (can we swap to calling them this, not Squad 0, it sounds SO much cooler) start fighting soon, even if it's just a training montage or something, then when the REAL fights kick off, we can spend more time watching the Bankai fly