Outgoing minister De Jonge wrote a letter to parliament, in which the possibility of a rental registry is mentioned:

https://www.rijksoverheid.nl/documenten/kamerstukken/2023/07/12/kamerbrief-over-actualiteit-huurbeleid-juli-2023

This registry can help monitor the government with various aspects on the rental market, among which the Good Landlordship Act or taxing.

This is just a letter to parliament, not a proposal to change or initiate a law. And of course, the cabinet is outgoing so it’s unclear whether a new cabinet will proceed with this idea in the future.