Hi Kathy,
I have looked into this previously and will be applying at some point.
I unfortunately can’t find a link to the details I found but to my best recollection it works like this:
Once you have obtained a UK gender recognition certificate it entitles you to apply for a new birth certificate, the new certificate is indistinguishable from any other certificate in that there is no reference to the existence of the original certificate with different name or gender assignment. Births, deaths, and marriages do hold a link between the original certificate (which is not destroyed), and the new one, and that information may only be obtained by relevant authorities by court order.
Nicole