Yes, Kat is right, Missy had just become a new gramma (again?) & did not want to chance anything with the pandemic, vaccinations, masks, traveling, etc. She does live in Tenn. & if we all remember, CAlif. had huge numbers of cases back then. The show recast, but evidently just temporarily, and when whatever the story was ended, the recast was gone, too. Ever since, they just have done without her, having her taking forever to settle her mother's estate in Boston.