Rowling's statement wasn't even explicitly true before the rise of transgender visibility. It excludes women who don't conform. I've lived with pre-menopausal women who didn't menstruate regularly and felt that they were "wrong" somehow because of it (some had underlying medical issues, some did not). To use Graham's analogy, even ignoring transgender issues, the orthodoxy there was privileged against the multitude of female experience.
Rowling's statement is true if your experience leads you to prioritize the orthodox. It's patently false if your experience deviates from the experiences that created it. The struggle in the conservation of orthodox values (e.g. sisterhood of women) and the visibility of heterodox experience (e.g transgender issues & the lived experience of women who's bodies don't conform to the stereotypes being used) has a lot of truth on both sides.
Rowling's statement is true if your experience leads you to prioritize the orthodox. It's patently false if your experience deviates from the experiences that created it. The struggle in the conservation of orthodox values (e.g. sisterhood of women) and the visibility of heterodox experience (e.g transgender issues & the lived experience of women who's bodies don't conform to the stereotypes being used) has a lot of truth on both sides.