I read the post and coach Kurasame said the same that Harimoto needed to expand his attack patterns using Ma Long's example.
Found another article that delves deeper into Miyazaki's opinion. Similar to China, it appears there are now 2 rivaling schools of thought in Japan.
2019/5/5
https://www.jiji.com/jc/article?k=2019050400482&g=spo
◇決定打はやはりフォアか
「バックでできることはバックでやる」。日本卓球協会の宮崎義仁強化本部長は卓球日本がどん底から盛り返せた理由を、バック側の球もフォアで打つオールフォアのスタイルから脱却したからだと、盛んに強調してきた。
バックはフォアよりラケットの振り幅が小さく、腰の回転を使って打つのでもないため、小柄な日本選手でも打球点を速くして攻撃的に使える。この2年、日本の若手は前陣でバックを多用する高速卓球で、中国などの外国勢を倒した。今までの日本と違う戦い方に、相手が戸惑った面も多分にある。
これにも世界は対応した。強豪国の選手でなくとも、相手の反射神経が良くてラケットの角度を合わされれば、速く打っても返って来る。体格の良い外国選手は、左右に振ってもラケットが届く。チキータ対策も練られ、バックの比重が大きい今日の日本卓球の特長が、得点につながりにくくなった。
宮崎本部長は「特にプラスチックボールになって球速が遅くなり、回転量が減った今では、決めるのに威力があるのはフォア。バックでは若干パワー不足。バックでタイミングを取ってフォアで決める方がいい時代になった。韓国は若年世代からそう指導している」という。
そもそも人体の構造を考えれば、フォアの方が強く打てるのは自明の理。乱暴な例えだが、アントニオ猪木のビンタも「フォア」だ。日本のバックが強くなっても、中国関係者は「最後はフォア。それは変わらない」と言ってきた。
*The Decisive Shot is still the FH
Yoshihito Miyazaki, Head of Development Headquarter of the JTTA, vigorously stressed that the reason Japan was able to return from rock bottom is because it has moved away from the all-FH style where shots to the BH side are returned with the FH.
Since the BH has a smaller swing than the FH and is not hit with the rotation of the hips, even a small Japanese player can use it aggressively by hitting on the rise. In the past 2 years, young Japanese players have defeated foreign countries such as China with high-speed table tennis that uses a lot of BHs close to the table. There have been many times where the opponent is confused by the different playing style of Japan.
The world has responded to this. Even if it is not a player from a strong country, fast shots can be returned if the opponent's reflexes are good and the racket angle matches up. Foreign players with good physiques can reach even if they swing left and right. Countermeasures for the chiquita were also devised, and the feature of contemporary Japanese table tennis with a huge focus on BH has become hard to score.
"Especially now that the plastic ball has slowed down and the amount of rotation has decreased, it is the FH that has the decisive power. BH is a little under-powered. This is an era to seize the timing with BH and finish with FH. This is how South Korea teaches the younger generation," said Miyazaki.
...Even if Japan's BH has become stronger, “It still comes down to the FH," said a Chinese official.