If nothing else, the ‘new’ design sheds weight by adopting the original diamond tail of the ATB instead of the low altitude saw tooth tail. That and I would imagine modern materials and design would shave some weigh compared to the B-2. We all agree it will lighter with less payload; we just seem to disagree on the importance. I agree with above post that B-21s will probably serve as almost more a fighter bomber role in a conflict when it is in service in numbers. I somewhat doubt it will be more forward based than current bombers, however.