I blame whatever Gamma-era dev told BattleLaf "hey, we need unit ready announcements for the Yak and MiG just in case we get the means to implement them in 8 years' time, but don't worry about doing any Airfield attack announcements, it's not like these units will need a building to be purchased from and to land at." I'll look into improving it but ultimately anything new like the airfield has to be a splice job unless someone comes and redoes all the EVA work. (And first I'd prefer to hear new radio commands.)