So one thing that a lot of people, including the author of the article, may not realize is that Chinese 'dialects' aren't really dialects. They are each different languages spoken by different ethnic groups, kind of like how Spanish and Italian are different languages but still related. These different languages are called dialects mainly for political reasons, with the main one being unification. It's useful to think of China as Europe, unified through force instead of legislation.
Anyways, I'm going to disagree with you. imo 茶 has the same meaning in different parts of China. It's just said differently in differents parts of China just as like it's called different things in different parts of Europe. The only difference is that in China it's written as the same character.
What you have described is exactly what happened in Qin dynasty 2000 years ego. Then those languages evolved together and all influenced what is the modern Chinese.
It is funny that this is the reverse process as how Latin evolved into Italian and Spanish etc after the fall of Rome.
The reason that China split and unite again and again is all the dialects/languages share the same characters even sound differently. The phonetic based Latin can easily evolve differently to match the pronunciations of dialects. That's why after Rome collapse there are many new nations and can not unite again.
Anyways, I'm going to disagree with you. imo 茶 has the same meaning in different parts of China. It's just said differently in differents parts of China just as like it's called different things in different parts of Europe. The only difference is that in China it's written as the same character.