Looks like it has shifted to a 767 from a 744, which probably explains the demise of F... I'd have thought you should have been notified - and offered the option to move to one of the 777's which still offer F....

ETA: I think this was discussed somewhere before, but search is failing me. Shifts from a 744 to a 767 WEF 29th October (e.g. the start of the Winter schedule).