That's assuming the purpose of the GRA was to force society to see and treat a man as a woman? Politicians need to clarify that this was their intent.
Off the top of my head, there were 48,000 people identifying as trans in England and Wales on the census, but fewer than 7,500 have a GRC. So by those numbers, we have to assume that a man with the PC of GR does not have a GRC.
If the government want a man with a GRC to be treated as if they are a woman, but a man without a GRC shouldn't be treated as a woman, we need a way of differentiating them. We cant use looks, we cant use passport or driving licence, we cant use GRC. Anyone can purchase any birth certificate.
So its up to the courts and politicians to clarify.