As the title already says, I am looking for datasets that have the following two characteristics:
(1) They are updated periodically (interval is irrelevant)
(2) When the dataset is updated, old data is not retained (or at least no longer accessible to the public)

An example of such a dataset is the Majestic Million dataset that is replaced each day with updated data: 
[info] https://majestic.com/reports/majestic-million
[csv] http://downloads.majestic.com/majestic_million.csv