I don't think it ever could.
Not even in alpha.
Either do I but the tooltip was something along the lines of "the okw has many aa solutions available to them such as the flak ht, luch's and base 20mm flak's etc"
It makes sense to have it shoot at planes if the ostheer 222 can do aa since the luchs is basically a beefier 222 with the same gun, they probably removed its aa ability in the end since they had so many stock options with the base flak and schwere auto shooting down planes on release.