"Firstly, paragraph (1) says that suitable and sufficient facilities must be provided. For a trans person, a suitable facility is one that matches their affirmed gender.
Paragraph (2) seems to require gendered facilities, and some argue this is based on “legal sex” as determined by a birth certificate or gender recognition certificate. [Note 3] However, if you read carefully, you will see it must be read without prejudice to the generality of paragraph (1).
And if you read very carefully, you will see that it does not actually require separate facilities—allowing people to use the same room at different times is enough to meet the minimum requirements under paragraph (2)."
You just have to read the legislation very, very carefully, and then it can mean anything.