For me the real mystery is whether they started inducting WS-10 J-20s into the Wanghai Brigade. We know for a fact that the 621xx series of birds are still using the AL-31 variant, but the only 622xx bird -- 62207, has its nozzles strategically obscured in the only footage we have of it.
You mean 6210x series and 6220x series right?
Because of the ABxCx numbers, the C has to be a zero if it is to still refer to 9th brigade at Wuhu.
In any case, I agree that it's not impossible that some of the 6220x aircraft might be WS-10 powered.
I feel like there is a good chance that only some 30-40 production J-20s powered by Al-31s have been produced. Depending on what the specific number is, they might've only produced enough Al-31 powered J-20s to distribute between part of Dingxin, part of Cangzhou, and part of Wuhu.