An interesting point.
The difficulty that trans women pose for gynaecology is that we don't have the parts of the female anatomy that a gynaecologist is principally interested in, namely a cervix, uterus, tubes, and ovaries. Yes you may have a vulva and vaginal opening, but even that is not quite the same in its construction as the "factory fitted" option.
For example the skin in the vagina in your case will be keratinised squamous epithelium derived from the ectodermal stem cell line, where a natal female will have stratified squamous epithelium derived from the endodermal cell line. It's a small histological difference and of no consequence to anyone other than an expert... but it's a difference – and therein lies the problem.
Another example – you will still have a prostate inside you, which makes a substantial difference to the arrangement of your internal and external urinary sphincters.
We probably actually need our own medical discipline, because in the current state of what can be achieved by medical rearrangement, gynaecology doesn't really cover the resultant anatomical mix. As better treatments come along that may change, but not for some while I fear.
**EDIT** Maybe I should add that in 30 years of being post op I have never needed a gynaecologist.