Of course, I mean that the size range disappeared, not the women for whom it had been desired. Half Sizes were replaced by Women's Petite.
I am still tracking down the exact change in standards, but it is clear that the dimensions and proportions changed, not just the name.
Here's the thing. If sizes associated with age (half sizes) do not exist, women over fifty must select clothing from the remaining size ranges based on the size, shape and proportion of their bodies. This sounds like a good thing, but there's this reality: we are not all Helen Mirren. We are also not 20-something plus-size models. Some of look like this, or will, if we live long enough: