This convention is widely practiced in Western journalism, but unfortunately it hasn't become common knowledge. As a Chinese person working in UK, I frequently have to explain my name order, despite the fact that most people have definitely seen "Eastern" names like Xi Jinping and Yao Ming in the news. I guess most people never asked themselves whether "Xi" and "Yao" are given names or family names.
Personally I welcome this change by the Japanese government. My hope is that this will raise awareness of the "Eastern" name order.
Makes me wonder if non-Japanese Wikipedia articles will change the surnames to reflect this.
e.g. "MIYAZAKI Hayao (宮崎 駿 born January 5, 1941) is a Japanese animator, filmmaker, screenwriter, author, and manga artist. A co-founder of Studio Ghibli, a film and animation studio, he has attained international acclaim as a masterful storyteller and as a maker of animated feature films, and is widely regarded as one of the most accomplished filmmakers in the animation business."
If this catches on, maybe there will be three eras of Japanese name order in English. Pre-Meiji, Post-Meiji, Post-Reiwa.