I feel like it's a lie because of how the Japanese have engineered their trains. Theirs have a huge leading "nose" structure to help them move the air in a fluid manner. I'm thinking the engineering behind that hasn't just suddenly been out done.
China's been working on these trains for over a decade now, there's nothing sudden about it. Also weird to think that what Japan did can't be replicated, if you look at the picture of the actual Chinese maglev train it too has a large nose structure https://www.cnn.com/travel/article/china-fastest-maglev-train-intl-hnk/index.html