2016 reportsHere is what XO of the ship is saying :
Source : http://english.chinamil.com.cn/view/2019-04/25/content_9488581.htm
So, for combat duties, the ship was not ready in the eyes of its XO at that time and they were working on SHIFTING that AFTER 2018.
Article excerpt
Xinhua News Agency's press release pointed out that: Recently, the navy has successively organized aircraft carrier formations to conduct live-fire exercises. Air-to-air, air-to-ship, ship-to-ship and other drills have been performed wonderfully in a certain sea and airspace in the Bohai Sea. The participating troops are mainly from aircraft carrier formations and the North Sea Fleet, with a total of various types of ships and dozens of aircraft participating.
Rear Admiral Yin Zhuo, Minister of Naval Equipment, revealed in an interview with domestic authoritative media that the "Liaoning" combat platform itself has formed combat effectiveness, but the number of carrier-based aircraft and the number of carrier-based aircraft pilots have not yet reached the standard.
Therefore, the reason why it is considered to be a training ship should be that thethe number of carrier-based aircraft and the number of carrier-based aircraft pilots have not yet reached the standard.