First off since this was first a Russian carrier I cast some doubt to the claim that it is unfit for their aircraft, at most its probably a retro-fitting to their aircraft and a pilot training issue. And they would not put it out to sea if they weren't ready to use it, that's just not the China way lol.
While you are correct that they could use that as a massive troop carrier, to a degree, it would make much less sense than using commercial tankers and cargo vessels and perpetrating a "sneak attack" invasion following sabotage and chaos caused by advance black ops team already in country. Ala, Homefront style.