I think we've all forgotten that the WWI arena patch intorduced an upgraded damage model. Last I checked/heard, it has not been implimented/integrated with the WWII content yet (and will take a lot of time), but we can assume when it does that damage will be represented in the game for all aircraft much better than what we have now and that until then things are gonna stay the same as they have been...
The damage model will not be like WW1. That's going to be unique to that arena, per some comments from HTC staff. What we'll get in WW2 (and we are already seeing this) is more parts, more finer resolution of damage. We will not get 10 chunks of wings to tear off nor loss of lift from bullet holes, like I think we have in WW1.
What we will see are more finer details, like left and right stabs, gear doors, visuals on flaps, elevators, ailerons, rudders, and overall improvements. It will not be like the WW1 setup though.