Belgium had anticipated the DAC 7 regulation and had already de facto transposed it into domestic law. In brief these rules entail that platform operators are obliged to inform and to share data on their users.
Specifically on this information sharing obligation, a judgment of the EU Court of Justice regarding a Belgian regional tax (tourism tax) was awaited, the result of which could indicate whether or not this Belgian preliminary transposition was EU proof or not.
Source Tiberghien