I think expressing a fear about taking advantage of in this day and age is reasonable. Enough things have happened to enough people of all gender identities and descriptions that "I am afraid someone will violate my space" is a totally valid concern. Trans individuals asked to change in the opposite gender locker room also may have this fear, in addition to cis individuals, adding a layer of complexity.
Does that necessarily mean trans women who are verified competitors in a sport need a separate space to change? No, it doesn't necessarily mean that, but I do think putting in place safeguards to protect against people who might easily use a space to view naked people is also a valid ask. Now, the specific safeguards in question, that gets tricky. Where do you draw the line? It seems unfair to ask someone to have identified a certain way for a certain amount of time before they gain access. It also seems unfair to ask anyone of any gender to feel unsafe to do their sport. But I think belittling others' concerns is not helpful here either when there could be a productive discussion around "what would alleviate your concerns?"