The ship don't change their control tower so no extra aa is planted in late war version of VIIB VIIC or XI, thought they show equipment in the slot. And if you upgrade aa.
And the main reason for that is in the UnitParts6VIIC.upc
[UnitPart 2]
ID= Turm_VIIC_B
Type= VIICConningTower ;Can only placed on unit parts slot of this type
NameDisplayable= Start of war Conning Tower
UnitPartInterval=1942-09-01, 1943-12-15
ExternalLinkName3D= NULL
HullTextureNameOverride=NULL
HullLightmapTextureNameOverride=NULL
HullNormalmapTextureNameOverride= NULL
MenuSilhouetteTextureNameOverride= Typ_7c_2.tga
So in KSDII, there are only four basic type of Ubaots , all variation look exact the same. And the AI uboats all missing deckgun and aa. It seems the game encouters a conflict so it rolls back to basic model for everyone.
Then I found they use upgrade slot to change conning tower manually, So you can change it in campaign, but the AI ship remain default and naked
Then, it cames to another old problem, lack of proper AA control , so I think I have to fix it manually again.