All ANSI standards are required to be maintained and updated periodically, or they lapse. That can be as simple as rubber stamping the last standard, but in practice, there are usually a few tweaks needed.
It hasn't been updated in any meaningful sense beyond C89, though.
inttypes was pretty big, right? I know it's just one header, but it's an important thing to have in the standard for a systems language.
C'mon it even has some kind of primitive generics support nowadays, which other modern languages keep ignoring.
C11 generic selection is basically not worth using and almost worse than not having "generics" at all. It exists so tgmath.h can be written without implementation magic but tgmath.h is kind of a garbage fire itself.