witnessed with:
BIS_fnc_removeVirtualWeaponCargo;
BIS_fnc_removeVirtualBackpackCargo;
BIS_fnc_removeVirtualItemCargo;
BIS_fnc_removeVirtualMagazineCargo;
those functions call BIS_fnc_AddVirtualItemCargo with 3rd parameter set to true, which adds the arsenal action.
behavior cant be turned off, as it is hardcoded in the above mentioned functions.
either a optional parameter to keep the arsenal action gone or setting it to false (would make more sense - if the action is not added with "AmmoboxInit" or adding content to the box the missionmaker might have its reasons) {F25650}