I think it would be a really cool feature, it would add a lot to the immersion!
I am aware that there are certain criteria for AI planes to spawn (number of parts, wings, etc.) but it is really disappointing when the same pool of 5 or so aircraft are the only ones spawning, especially when those 5 aircraft are goofy, unrealistic ones that I never wanted to spawn in the first place. I have been playing this game for almost a decade, and this has been bugging me for years.