We’re well beyond my knowledge with programming, but my understanding was that it’s just a retail wow framework… but all the actual data is legacy. So my understanding is that transmog isn’t just flipped off, it’s entirely non existent in the data set being used.
And even if we could copy/paste the functionality for it into the code, there is still an issue with the UI for it, and the complete lack of NPCs/buildings made for it in a wotlk data set… No version of the transmog building exists in the old world/non flying version of the game.
EDIT: If my assumptions as to how the programming side works are way off, by all means correct me, I’m genuinely curious to learn more about it.