I assume they received old J-20s retired from another brigade? Since supposedly all new J-20s are J-20As
Scramble doesn't mention that any J-20 brigade has divested from its aircraft.
My theory would be that the 2nd AB received its J-20s in 2024 and that we only saw evidence recently due to the PLA's improved opsec.
Note that the 2nd AB used to fly J-10Cs, a type which AFAIK has been out of domestic production since ~2022. Yet, in late 2024 we saw that the 44th AB had transitioned to the J-10C. As such, I'd suggest that the 44th AB's new J-10Cs are in fact the 2nd AB's former J-10Cs, transferred after the latter unit received new-built J-20s some time last year.
In turn, said new-built J-20s were probably part of the last batch produced before the retooling of the assembly line for the J-20A.