I believe BWI has for many years subsidised that route for BA, ensuring it gets a daily service. I think also it's possibly the last longhaul route to move over from a 763 to a 788.
CVG is pretty much in the middle of all of them - have memories of flying a DL MD-11 into Gatwick many years ago. Presumably that's still a big fortress hub for them? Might make the yields quite attractive for BA if they can maintain prices.