Others have noted, and I tend to agree, that it’s not so much about the loss of money in a nation where they don’t have much of a footprint anyway (less than 1/5 of 1% of their members live there).
What is likely more troubling is the precedent it sets. If a European country determines that JWs are not to be a recognized religion due to their disfellowshipping policy, what’s to stop other nations from doing the same, perhaps with more dire consequences (loss of tax exemption? Loss of property?).
Expect them to fight this with everything they’ve got. They’ll defend their “right” to control members through the blackmail of enforced shunning to their dying breath. Without that level of control the whole shebang dies.