I don’t disagree per se, but the article says that the plane operates at 20,000 meters ceiling, Wikipedia says SR-71 had 26,000m operational ceiling, so this thing is high up, but not as high as the blackbird. Not sure how much of a difference that makes for the air and heat issues.
The company that makes this thing is making ballistic super sonic rockets for China, so I think the implication in the article is that this thing is basically a rocket with wings.
Per the article the prototype was flow at around 20,000m and they’re specifically going up there for the efficiency reason. The design also has a “high lift-to-drag ratio” that is apparently helping out.
This one has some more detail, no way to confirm its veracity however. https://theasialive.com/chinas-yunxing-jet-completes-test-flight-eyes-supersonic-commercial-travel-by-2027/2024/10/29
It could all be marketing hype, but there are a couple other companies in US and UK working on similar projects.