BA could make CW 1-2-1 just by numbering the seats differently!
current 1B-D-G-J (front facing) would become 1A-E-F-K. Current 1A-E-F-K (rear facing) become 2A-E-F-K. 2B-D-G-J become 3A-E-F-K, 2A-E-F-K become 4A-E-F-K. Nominally doubling the number of rows, bingo: a 1-2-1 cabin.
If you look at seatmaps for the 'new' AB and IB cabins for example, they are really also 8 accross but they are still called 1-2-1. The only space gained on these layouts is the space needed for direct isle access, but then you lose space around the feet (footwell) compared to CW...
BA Marketing, I won't charge you for this idea but will happily accept some complimentary upgrades... ;-)