It is all speculation at the moment and until 26 October when the first 787-900 departs for DEL, we will not know for sure.
I do not mind like the workmanlike J, which current CW is, as long as F is a product where the seat and service are a couple of notches above. Something to aspire for and their are people willing to pay for such a difference. Otherwise the difference between BA F and other airlines (such as QR 787 J) is minimal.
if BA do not see F worth the investment to bring it up to competitors standards, the. They might as well save the money and invest in a J product that stands out.