Tphuang hasn't posted in a long while so I can't get a reading on what his thoughts are. I wouldn't take the insider's words as gospel as he works in Liyang, not Liming, so he would only get second-hand or nth-ordinate-hand accounts of Liming's progress. He even says that himself; that of all the engine programs in China, he knows the least about the WS-15. Nonetheless, the secondary/tertiary sources that he has access to, while not perfect, are still more reliable than our conjecture.
The 2016 ground test rumour is ambiguous as to whether it's a test of just the engine core or a complete tech demonstrator. The doesn't contradict the insider's accounts at all. The article's individual-in-question said this: "the engine's development is proceeding well. We have also begun to design a next-generation aviation engine with a thrust-to-weight ratio that is much higher than that of current types." I'm interpreting that to mean there are two separate engines; one that will soon be mounted on J-20, and another next-generation engine, probably WS-15. So you're agreeing with me in that the J-20 will likely mount WS-10Bs before WS-15 is ready.
As an aside, the documentary from CCTV that said the J-20's engines were manufactured by Liming was ridiculed by literally every single experienced PLAAF watcher on Chinese BBS, including Huitong. There is no doubt that current J-20 engines are from the AL-31 family, even if the exact variant is unknown. And there is serious doubt that Liming is able to manufacture the AL-31 in its entirety because if they could, why buy from Russia?
He even says that himself; that of all the engine programs in China, he knows the least about the WS-15.
I know; I saw his post about the WS-15's nozzles being serrated and stubby.
he knows the least about the WS-15
I'm surprised that he's even on CJDBY if he's a Liyang employee. Isn't aeroengine development too sensitive in China to post on internet forums (he even posts his picture although it may be fake). I know some people's weibo accounts got shut down after they posted "confidential" photos and information about the PLA. Surely, his account would be scrutinized?
The doesn't contradict the insider's accounts at all
I believe it is referring to the WS-10IPE variant instead of the WS-10B, giving thrust of around the 150kN level which is comparable to the F-22. But regarding the second part, I disagree that it's referring to the WS-15 because it's probably unlikely that it's still in design phase, especially if we heed the ground testing rumors. Btw, any indication of when the WS-10IPE is going to be mounted on the J-20 from the Liyang "insider"?
CCTV that said the J-20's engines were manufactured by Liming was ridiculed
For the record, I never suggested the Liming documentary to be true or did I used it as evidence. It is probably more likely a mistake (especially given the CCTV-4 channel) than a confidential leak.
And there is serious doubt that Liming is able to manufacture the AL-31 in its entirety because if they could, why buy from Russia?
Some say the nozzles and some other parts of the engine (FADEC?) are manufactured in China. Additionally, I haven't heard of any engine transactions between Russia and China in recent years, meaning the latter probably has a large supply. Surely the Russian media would gloat about a large engine sale? Regarding the variant theory, I side with @Deino because I don't believe the J-20 to be "drastically" under-powered in its current flight regime, corresponding with the AL-31FM2's high thrust.