With Christopher Nolan ending his Batman series soon how would you fit Batman into a Justice League movie? Would you reboot the series in time for a Justice League movie? Would you have Christian Bale appear one last time as Batman in the movie? Or do you have some other idea?
Personally I would go with the second option simply because I think a reboot would be dumb so soon after the ending of one series. If they decided to push a Justice League movie for 15-20 years down the road which I highly doubt DC would do, then maybe I would call for a reboot but not if before.