several months ago, they were already forms sent out to congregation members requesting their permission to store and use their information. - Doubty
The EU ruling was not about the congregation collecting information about its members. The cult is already compliant in that regard.
It was a ruling that individual JWs writing down information about householders, Not-homes or Do-not-calls is also covered by the legislation.
The cult were opposing this and have now lost the case in the highest court in Europe. No further legal redress is possible. They must now decide how to change their practices in order to comply.