As a summary: two years ago the transgender law was approved, it allows trans people to change the male to female or vice versa on their ID and birth certificate if they identified as such without medical requirements, really simplifying the process that had to be done before.
The Court now ruled that this law is unconstitutional and excludes people who don’t identify as either female or male, and this has to be adjusted by parliament now (could be done by adding a third or more gender options, or by removing it entirely, that’s up to parliament to decide). This will probably have far reaching consequences in everything involving gender.
The other decision made by the Court is that this gender change cannot be irreversible as the law said. So genderfluid people should be allowed to change multiple times. There is a wait time of three months when requesting a change of their gender and it may be disapproved if they suspect fraud or misuse and the Court ruled that this is sufficient and that a second (or third or more) change does not have to be achieved in family court which up to now was the only option.