In some cases for things like stealth tech, sure. In most cases though, where there's an obvious commercial aspect to successful research, we see things fast. When there's a military invention that could lead to something like a microwave or nylon the company behind it want to reap billions from selling to the public as soon as possible.
This is one reason why I find stories like this one unlikely. If we assume this object is, say, a Chinese spy drone, why would the Chinese use this amazing new tech for something as mundane and boring as a spy drone? They could turn it in to a commercial engine, mount it on some aircraft, and completely dominate the air travel and air freight. As far as using technology to crush your enemies goes that would have a much greater impact on the US than watching what the country is up to from a drone.
This is one reason why I find stories like this one unlikely. If we assume this object is, say, a Chinese spy drone, why would the Chinese use this amazing new tech for something as mundane and boring as a spy drone? They could turn it in to a commercial engine, mount it on some aircraft, and completely dominate the air travel and air freight. As far as using technology to crush your enemies goes that would have a much greater impact on the US than watching what the country is up to from a drone.