Because CCTV specifically said "王海大队", which is almost certain 8 jets, I can't tell how many j-20 they have now, but at that very moment, yes, only 8 or 9!
If a news report says Glorious Red Army 3rd Battalion has received new vehicles, you don't interpret that to mean only 3rd Battalion has received new vehicles; that entire brigade has begun receiving new vehicles except the journalist chose to only interview 3rd Battalion.
9th Brigade began receiving J-20s in early 2019, it's been more than a year. It's highly likely they've finished receiving a full brigade's complement of J-20s by now if not much earlier.