Ace no longer active?

[Materia]

How do aces work exactly? 

I have them all selected in workshop, I shoot them sometimes, just for them to die, and then respawn, die again, and fly again, I get it, they are meant to die at the historical date etc., but for example Lanoe George Hawker, when I search in aces tab, and I view his profile has "ace no longer active - last kill made on x". Bio says he should still be flying. I think I got him 3 times. Other aces often have limited info, and intel not available at the moment. 

When I shoot aces down, does it affect anything? Some I can't even find in the database at all.

Edited September 15 by Materia

[Rick Rawlings]

I think the main thing is they die on their historical date. I suppose it is possible that they are not active when they were historically on leave or out with wounds? I haven't really followed it up in that much detail. Maybe someone else will chime in!

[+Polovski]

Aces need a LOT of data, and many are not complete.  Perhaps his data is not all there.