If the yeast is only a month old, I wouldn’t use a starter. If it’s three months old, I would start thinking about doing a starter. If it’s four or five months old, yes definitely I would like a starter. Pretty much the same as I ever did with the previous packaging. Old yeast is old yeast, at least when liquid. (Dry yeast is a different beast altogether, no starters needed, ever. Which is why I use dry almost all the time now.)