I booked a deviation ticket two weeks ago to NRT. The Corp travel dude (Richard - who happens to be by far the best and most competent employee at the place) told me they have a list to reference by airline that states whether lie-flat seats are available for each variant. Ex: AA 777-200s don't have them so higher class of service is authorized. AA 777-300s do have them. AA 777-W is a code AA uses for a flight when they haven't decided which variant will be on that particular flight. This does warrant higher class of service. Of course if they swap tails at the last minute all bets are off. It's basically AFU and the language in the contract allows Corp travel to determine my class of service. Richard hates it too btw.