Yes and no.
Of course it's a victory for common sense, to protect the right of sane people to know that mammals cannot change sex and that there is no scientific evidence for the proposition that a human being can be born in the "wrong" body for their personality, personal tastes, worldview, outlook etc.
OTOH it's not a belief. It's actual material reality that sex is immutable, fixed, real and important.
I feel as though one day, we'll have to go to court for the right to believe that the Earth isn't flat and that it goes round the sun.
This is obviously a brilliant outcome in the real world but in terms of what it means philosophically, I find it a bit disturbing. We shouldn't have to fight for the legal right to express fundamental material truths. That we have to in the early twenty-first century, is actually very worrying and shows the sheer power of the trans lobby.