I think BCC will run until November as a contingency to see if core will actually implement 2x. If core does not, then BCC will be 2x. If core does, then BCC goes away. It's quit simple its really up to core to decide if they will honor 2x or not. BCC is just there as a backup because with SegWit being an irreversible change, any engineer/dev/ops team would like to have a contingency regardless of factions, its a saftey measure..