These were exposed in a nonanonymous fashion until recently. Removing those made sense, however for statistical analysis and metric reporting, they should remain exposed in an anonymized fashion.
For example, how many % of users use the MonoBook skin? Or how many % of users have their language preferences set to something other than English on English Wikipedia etc. These reports are periodically generated from Tool Labs, but are now broken due to their removal.
These reports never needed the user-specific information. The reports only used the user_properties table because they were absent in user_properties_anon.