Last Jun 24 was the first flight of the full-spec KJ-600, as in flying with the AWACS radar. But we saw J-20 with TVC engine posted on Jun 25. Apparently today the J-20 with WS15 TVC took flight, as hinted with the flying J-20. However there is also hint that only one of the engine is WS15 with TVC. Another hint, the poster ruled out WS10 TVC. Think about it, why test with only one WS10 TVC when it's abviously fully tested, no matter WS10 engine itself or the TVC, there's no point in testing WS10 TVC. So what all these hints mean is that blurry J-20 is flying with WS15.

KJ-600 is said to be the one flying on Jun 24.