The Kanji for Mitsubishi is 三菱, which literally means “three rhombus”. It is possible that they were independently invented, but the hypothesis on family crest crossovers still feels more likely
The shape is somehow associated with the name mitsubishi, possibly through visual or phonetic punning that is common in pictogram-based writing systems and tonal languages. Mitsubishi the name is more widespread than this one family or this group of companies, and the symbol appears to have long associated with the name per se rather than this specific mitsubishi. Mitsu sounds like three, I don't know what the rhombus connection is.
That shade of red has a specific proper name in japanese (think like alice blue in english) and has long been associated with japan by the japanese.
I don't think any of this is a coincidence there's a connection between all this stuff. But I don't know what it is and I don't think the article author does either.
I hadn't heard of that one [0], the example that comes to mind is "Canary Yellow", but I suppose that's not so bound up to a specific cultural history.
> pictogram-based writing
Incidentally, this Chinese brand:
https://en.wikipedia.org/wiki/Wuling_Motors
...has a logo that's rather reminiscent of Mitsubishi's, and literally means "five rhombus".