CX does exactly this -- but for F pax (perhaps limited to revenue F tix). I've always received a voucher for the JFK BA pre-flight dining when traveling on CX during dinner hours.

The BA dining menu is dismal in terms of quality and I've chosen to only eat soup/salad. Otherwise it is things like salmon and roast beef, but not Balik salmon or even smoked salmon Now Elemis spa treatments would be much more worthwhile.