Well, I do not know....to what the US wanted for LRS-B, rather than simply going for a B-2 analogue, which is obviously an advanced capability but is too costly and not flexible enough for service in the latter half of the 21st century
Compare the Northrup Grumman proposed LRS-B concept:
To an actual photo of the B-2:
I believe the LRS-B is a bit smaller...and looking at the intakes, perhaps aspects of the form are more similar to the "cranked-kite" layout like the XC-47B...but they still look pretty darn similar.
I am sure in terms of forming and stealth, the USAF has learned many things since the B-2 and have incorporated those lessons into designs like the X-47B, the RQ-180, and now into this aircraft.
I guess we will have to wait and see what they actually build.