I do not think the anneal temperature from 1950-2050F makes any difference in permeability.
This is a very stable austenitic SS, martensite induced ferromagnetism will be very limited due to high contents of Ni, Mn, N austenite formers. Anneal at any temperature gains no much in lowering perm. A tiny bit of ferromagnetism (Perm <1.01) probably comes from a tiny bit of remained ferrite.
Being said, the ferromagnetism could also origin from disorder/defects (say APBs), anneal can anneal out such disorders, leading to a bit lower permeability. Although the contribution from disorder is probably very low, it could be possible to decrease perm say from 1.006 to 1.005 (may or may not significant). So anneal and un-anneal could still make difference for this alloy already with a very low perm, but 1950 and 2050 make no difference because both are high enough to remove disorders.