If you suggest "If Cantonese being included in `zh` in OSM here, then its arguably this creates problems for, at least, Wikimedia sites using OSM." , then it seems you need to discuss a proposal with HK and Macau to redefine `name:zh=` to mean Mandarin, and start using `name:yue=` by standard. However, redefinition of such standard usually doesn't work. 