I don't really understand why Finland is doing this. I don't agree with many JW doctrines. However, I believe that a group of people should be able to excommunicate whoever they want from their group. This is called freedom of religion. It sucks, I know. But I would rather have my own personal freedom and allow JWs to continue shunning. I don't really understand the need for governments to manage shunning. Its called personal responsibility. If a JW parents wants to shun their child, well that sucks! But, shame on them. Its their responsibility and they will have to answer to the creator.
However, if Finland is worried about child abuse cases being dealt with in the congregation and not reported to them, that is a different story and completely legitimate.
And also, Finland screwed their sovereignty when they signed into the EU. Even if they acted against the JWs, the JWs could appeal the the EU high court.