Even ol' Bubba Boeing dropped the idea of BWB airliners after receiving some very negative passenger reaction to the seat layout proposals...
Just consider this. In a normal wide-body airliner, such as the superlative Airbus A330, if you have an 8-abreast economy class 2+4+2 seating layout, the outermost passengers will experience a vertical motion of about 27" if the aircraft banks at 15deg - which is a normal option for 'passenger comfort'. To carry 240 passengers, you will need roughly 30 x 8 abreast rows.
If you carry 240 passengers in a BWB with 'amphitheatric' 24-abreast seating arranged in 10 rows, you will need 6 aisles for access / cabin service etc., leading to a 2+4+4+4+4+4+2 seating layout. Which means that the outermost passengers will experience a vertical motion of 27" in every 5 deg bank - I doubt whether this will be conducive to passenger comfort as, unlike a 15 deg AoB turn, a 5 deg AoB bank will probably be reversed to wings level rather sooner. Much as the Spams like their rendition-class seating in tanker-transports, I predict that by 2025 even they will have recognised that military passengers have basic human rights too and that ultra-wide bodied aircraft with 'amphitheatric' seating won't be acceptable.
Boeing once proposed a design with 10 passenger bays, 5 per deck. Most bays contained 2 triple seats (or 1 double and 1 triple) plus a central aisle. This required no less than 10 aisles and would have meant very few passengers indeed would have had any outside view; probably rather important to the poor souls in the outermost seats where every 4 degree twitch in turbulence would feel like a turn reversal in a normal aircraft.
Which leaves either single-role tankers, or tanker/freighters. Either of which would be less flexible than a true multi-role tanker transport such as the outstanding KC-45A.
The BWB is an elegant idea, but rather seems to be a solution to a problem which doesn't really exist.