there are no women's spaces
Of course there are. There will be toilets. If a male gymnast identifies as a girl and the club won’t let him use the girls’ toilets they will be in breach of this policy. It says in the policy:
Gymnastics Australia supports the right of people to use changing and bathroom facilities which best reflects their gender identity.
Within Gymnastics Australia and Australian Gymnastics Organisation managed facilities, people have the right to use changing and bathroom facilities which best reflects their gender identity.
Why are you trying to minimise the impact this has on women and girls? If just one girl in one female toilet in one club is negatively impacted by the presence of one male enabled by this policy, that is enough. How can an institution address its historical safeguarding failures that allowed girls to be abused while also creating a huge safeguarding loophole?