I was under the impression that "alkoholfrei" / "alcohol free" could be up to 0.5%, whereas 0.0% really needed to be without any alcohol. Your link is only about the first case, if I read it correctly. They do state though that "without alcohol" should really be without.

Edit: further research seems to indicate that it is unfortunately not quite clear and you are correct: ". Sobald der vorhandene Alkoholgehalt mindestens 0,05 Volumenprozent beträgt, ist die Angabe „alkoholfrei“ um die Angabe „(< 0,5 % vol)“ zu ergänzen." - https://www.gesetze-im-internet.de/weinv_1995/WeinV_1995.pdf -> only once you exceed 0.05% do you need to declare <0.5%

Very disappointing indeed. Why not have them call it <0.5% and <0.05% and have the customer take an informed decision? Of course because the industry then says: "Dear government this is too hard, let us deceive the customers 🥺"