kirge traped ichigo in the dangai right? because if so then i think kubo is setting up the return of dangai ichigo and what i think is going to happen is while ichigo is traped, he will try to break the cage he is in without any luck and so he will talk to zangetsu about why his bankai cant be taken and why cant he break the cage, zangetsu will make ichigo train with him again while telling him the answer and as we all know, dangai ichigo can only be obtained by him training in the dangai which will give the soul reapers a fighting chance.