This is sadly probably will not happen. Not talking about the replacement of B-1 and B-52, but I am talking about the replacement being the same "outlook" as a civ air.
Read somewhere (probably Air Force magazine) a long time ago back when I was still in the Military, there were an article that talks about the future bomber and why they don't make the bomber bigger like an airliner? The problem is, they don't want the signature of a military aircraft to look like Civ Air, because that would jeopardise the civilian flight in war. While Boeing 707 and 727 were used by the USAF, but all of them are without offensive capability
If they started making bomber out of 727 or aircraft that emit similar signature of any civ air, that would put all aircraft at risk, it maybe the biggest spoof of all time but then you are talking about hundred, if not thousand aircraft being at risk, that's why they won't make these bomber bigger or as big as the civ air........