Quite possibly. I do tend to see it as a backup and a bargaining card for the next time they negotiate with Saturn-Lyulka for buying the next batch of engines. The thing is, I see the buying of the specialized AL-31FN engine from Russia as a political tool for China to keep good relations with Putin and Russia. Its not unusual for China to use purchases as a political tool, and I would put the S-400 and the Su-35 purchases in that category. By helping to subsidize Russian engine manufacturers, it makes it easier and cheaper for the Russians to make their next generation fighters. So this is an important point for the Russians. China in turn gets all sorts of political benefits such as access to Russian oil and gas, and someone watching their back in Central Asia.
WS-10 would have been ripe for use with the J-10 for some time now. It is politics that prevents this and politics will prevent it again. Do you know the Russians built an entirely new plant just to make these engines for the J-10? Breaking this bond will put many Russians out of work and unhappy.
If Russia invested into an entire production line for AL-31 series for J-10 then it's their bad luck. I think China should delink its Aeroengine manufacturing ecosystem ( which has not even matured to a full spectrum ecosystem meeting all of PLA demands yet,tbh) from Russian or any foreign state geopolitics.
1. Russia never allowed China to have a manufacturing line for AL-31 series. It said NO when China's engine programs went through a rough phase ( 2000 - 2015). Could have had some arrangements akin to that between Indian and Russians. The Russians allowed India to have a manufacturing line for AL-31FP for their MKI.
2. Russian engines are unreliable when contrasted with Western products. Whether it be French Turboshafts or North American/British Turbofans... the Russian products were/is inferior. Why China continue to depend on Russia's powerplants is beyond me ( especially as of 2019, when China is not exactly "cash-strapped").
3. A J-10 crashed in Tibet last month. That J-10 had Russian AL-31 series engine. Why should China risk its increasingly complex and expensive fighter air-frames to damage and disintegration when it has in possession an engine that is more reliable? ( WS-10 failing is very rare - as per open source information, anyways).
4. China should be having a great relationship with Russia. There are no arguments there. But China needs to have a strong local engine manufacturing and innovation base too. That base gets harmed when China invests in a foreign production facility.