My theory is that this started it all:
This classic masterpiece from 1986 by Miyazaki Hayao was an immensely popular Japanese film worldwide and possibly the first Japanese production to comprehensively and continually permeate the Chinese world.
To those who read Chinese and know the name of the film in Chinese, the Japanese title also reads 天空之城 and thus people conjecture that の＝之 and by extension, の＝的 too, since 之 is more common in cultural writing or Classical Chinese than everyday vernacular, where 的 is more common.
Soon, this conjecture became accepted as truth since everyone drew the same conclusion. The marketing people soon appropriated の to denote high quality, since Japan in the late 1980s was an economic powerhouse and its products and services were seen as top quality, the way the Made in Germany is assumed to be top notch too.
As Japan cemented its position as the coolest country in the world, the use of の became even more widespread, for anything that wanted to invoke that same trendy cool factor.
If you want to market something in the Chinese world as trendy, cool, or quality, use の and hope that there won’t be a geopolitical crisis during the campaign!