Only someone with a bias could go from "Including more people" and call it "erasing you".
OK, that's my first, unconsidered liberal reaction. A more thoughtful response would be to ask "Is this going to help or harm the purpose of girls' sports?" And then I'd ask, "What is the purpose of girls' sports?" Is it to build lifelong habits of being active? Is it to teach hard competition? Is it to create a parade of scantily clad girls running around? I mean, start from first principles and go from there.
Having people who are genetically male physically compete against people who are genetically female might not be so great, if you want to see how well a person who is genetically female can perform. It would be like genetically altering some wrestlers to have chimpanzee strength muscles. Everyone else might as well go home.
But excluding someone from healthy activities seems wrong, too.
Perhaps @
xerxe's solution is best.