Any information that is uploaded to any 'cloud' server is likely to end up in the hands of somebody else. Be that the government or an advertising agency.
If I were in China, I would definitely use a third party app to control the Phantom. If I were doing anything remotely dodgy I would do the same and never take a smartphone with. The Fine Article was a bit unclear as it implies that the DJI GO app always uploads the telemetry data to the DJI servers. AFAIK, it does that only on command, i.e., when you ask it to sync the data. Of course, it could do so surreptitiously and we would likely never know it.