Summary
The Security-Team recently completed an audit of the configuration file maintain-views.yaml, in order to explore whether wiki-replicas pose some privacy risks for the contributors supporting Wikimedia projects. As part of the conclusions, it is recommended that gender data be redacted from replicas, irrespective of whether users disclosed it in their preference, willingly or not.
Broader context
Wiki-replicas currently allow users to pull information on a user's gender, provided that it was disclosed in their local or global profile preferences. Below are illustrations of a queries allowing users to collect details about gender from the centralauth_p database.
SELECT gu_name, gp_value as gender, gu_home_db as homewiki, gu_registration FROM global_preferences LEFT JOIN globaluser ON gp_user = gu_id WHERE gp_property = 'gender' LIMIT 100;
Here is a similar query run on eswiki_p, which highlights Spanish Wikipedia editors who have disclosed their genders.
SELECT * FROM user_properties WHERE up_property = 'gender' LIMIT 100;