China’s growth is unmistakably slowing down. And it has been since the 1990s. China’s percent change in real GDP growth was negative 62% of the time (16 of the 26 years between 1991 and 2017).
Musk conflates the trend of the growing importance of UAVs to mean that they will soon replace manned aircraft. The real trend over the past two decades is of drones augmenting the capabilities of our other air (and ground) weapon systems, not displacing them.