Looks like it was more a political stun than anything really wanted or useful to the population: https://www.jstage.jst.go.jp/article/jrca/15/0/15_KJ00009911... (when reading the conclusion)
As a Korean, I second this assessment. The "Cia-cia" project is widely viewed as a misguided attempt to sell an unusual writing system to a tribe living in a sea of other tribes, all using Latin alphabets. Just imagine how much technical issues these poor people would face, should they actually adopt Hangul, when the entire remainder of Indonesia uses Latin alphabets.
Surely, Japanese article must be trustworthy when it comes to things related to Kotea! lol
I expected that kind of remarks. Contrary to Western and Korean beliefs, Japanese researchers aren't obsessed with shitting on South Korea 24/7. There's a lot of individuals genuinely interested other languages and cultures, studying things like the Korean speakers in China's Yanbei province. In the article I linked, there are more references to research articles on the topic written by Japanese than what exists in English.
I can't blame them because it sure looks that way to people who's exposed to Japanese online culture. The ever-growing netto-uyoku (far right trolls) and the general public's reluctance to challenge their views is a problem that's been allowed to continue for far too long since the 2 chan days. Japan needs to find a way to de-radicalize these trolls. Even more so now that corrupt politicians are manipulating them to escape justice [1][2].