No, he never claimed that the J-20 was powered by the Russian engine.
But he had leaked the WS-15 being powered for the J-20B since 2017.
But in aeroengine design there is nothing like coincidence. So why do all WS-10 variants look more or less the same and this one should look like an exact internal and external copy of an AL-31?? It simply makes no sense and even more does not fit to any report from other most reliable insiders who claim the WS-15 is not ready yet; and surely not in 2011.
IMO this old fellow is simply wrong.