I think that means that you wouldn't be able to give such a name in cases where it has become a standard for the other gender, meaning it would be tricky to add new neutral names. It's also quite new additition so I don't think there are any cases that have went to administrative court yet.

According to https://www.kotus.fi/kielitieto/nimisto/henkilonnimet/etu-_j... the standard for same gender is 5 people that are alive, i.e. once 5 men and 5 women have that name, it could be given to either gender. Not sure what would happen if there was a huge imbalance though (like 1000 women with the name & 10 men). At least Rauni and Kaino have been granted to both genders after the law came in effect.