As a registered AUR user, I have just received the following email.
Dear AUR user, The next aurweb release, which will be released on 2017-12-03, includes a public interface to obtain a list of user names of all registered users. This means that, starting on 2017-12-03, your user name will be visible to the general public. The user name is the account name you specified when registering, and it is the only information included in this list. Any other account information, such as your real name or your e-mail address, will not be retrievable through this new interface. However, note that some of that information might already be visible directly or indirectly in other parts of the AUR web interface, such as your public profile or content you submitted to the AUR. If you do not agree to this change, please delete your account by logging into the AUR web interface, going to your account details page and clicking the account deletion link before 2017-12-03. This account deletion is permanent and cannot be undone. Thanks for using the AUR! The Arch Linux Team