How is a mockup a demonstration of superiority in this domain? The author is not making sense.
There is also the issue that US does not export its advanced drones to other countries, and does not allow potential visitors to check them out.
Nevertheless, China dispatched a delegation to Iran to study the RQ-170 Sentinel drone which fell into hands of Iran in 2011. It is possible that China have a functioning prototype by now.
On the other hand, RQ-170 platform is evolving - a new variant was spotted in 2017:
http://www.thedrive.com/the-war-zon...0-stealth-spy-drone-appears-at-vandenberg-afb
The endgame is the next-generation RQ-180 drone which will be autonomous to large extent, and with the capability to defeat other aircraft in combat. This drone would be the unmanned workhorse of USAF in the near future - slated to replace MQ-9 Predator.
An RQ-180 prototype already exist (hints from informed sources), but its developer have not made it public yet.
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MQ-9 Reaper now have air-to-air engagment capabilities - the first for any drone:
http://www.thedrive.com/the-war-zon...reaper-shot-down-target-drone-during-exercise
- an important development for RQ-180 program as well.