Yes. Private messages are by default available to “trust level 1” users, and we set them to “trust level 2” following the advice of the Legal team. This and other privacy-related details are explained on User privacy considerations in this forum.
We have modified other trust level defaults based on the Wikimedia Space experience (i.e. allowing everyone to edit wiki posts). If you want to discuss trust levels and features, we can do this on a new topic.