Dobs, I have wished for this before myself. Let me break down why it probably will never get added. First, furballs are a big part of AH. While the same cannot be said about WWII (not many furball missions), nevertheless it is true of this game. The one thing that distinguishes a gamer from an historical participant is score. Those that prefer the furball claim that the people wishing to 'clean up' their scores by correcting this problem with 'fighter' vs 'attack' would only increase the variance between the furball aficionado and the historical aficionado vis-à-vis score. So really, the guys that hate score are arguing on the basis of score.
Historically, it wouldn't matter. A mission is a mission, but the official record would indicate what type of mission you were on and which kills resulted. So, in the end the real problem is that the game does not distinguish one type of kill from another, and so you have to choose before you launch. I think that the attack category should have greater weight of influence on the score page, precisely because you are carrying bombs, and rockets. However, the launch button has weight now because otherwise it would also have to track each bomb or rocket you just dropped as you were engaged. I hope that makes sense to you.
Just wait until you repeatedly rearm for 20-30 kills and then discover you are in fighter mode. Yeh, . . . I'll just go ahead and take those kills now. . .