Negative.
The standard written Chinese "書面語"/"书面语" in Hong Kong is actually the same writing system of written Mandarin with some Cantonese terms even when reading them in Cantonese, and the written Mandarin place names are actually the same Simplified/Traditional Han characters used in Cantonese, which makes them written identically.
Also, using `yue` in `zh` would broke across lots of sites/apps including Wikimedia Maps, Android as none of the Mandarin websites use lang=cmn-* and all of them use lang=zh-*/values-zh-* including OSMAnd, Wikipedia, Wikidata, other Wikimedia websites, the Taiwanese Goverment websites, and more.