I also read that there is some religious sentiments based on this as well, some local religions feature ancestor veneration and some of those religions have a taboo about wearing clothing of a certain style in certain contexts (re: wearing period appropriate clothing of a warrior on a battleground might provoke the spirits). That informs this law to some degree as well, but I was unable to find specifics, it was only mentioned in passing by a single official that said they are trying to avoid public outrage in this context.