At first I suspected that it was just a boolean variable -or whatever the heck they're called- and the code could be easily changed but since my knowledge about programming isn't particularly extensive, I chose not to swell more on that theory.
Without detailed knowledge of the graphical tools they're using we really cannot make any claims about the ease or difficulty of these tasks, and anything we say is wild and baseless speculation. Here's some baseless speculation to start us off!
- What if the models for males and females of the various races are built on custom presets and the adornments would require additional contouring work that has not yet been done for both sexes?
- What if the models actually use a different set of incompatible attributes for certain feature hooks (like flowers in hair) and they'd have to write them over from scratch for the other sex?
- What if the various helmet and headgear models have scripted behavior for how they reshape the hair and adornment textures to fit smoothly underneath, and the sex-specific adornments simply don't have the reshaping work done for the opposite sex models, leading to vast clipping issues?
Really there's just so many things that can go wrong, it's quite unlikely to be a simple boolean value change.