By default, each time someone new joins a group, Guild posts an automatic announcement to the group.
You can choose to turn off new joiner announcements.
- Go to the web admin
- On the 'Groups' screen, tap the name of your group
- Tap 'Advanced settings' at the top of the page
- Turn off 'New joiner announcements' (switch to grey).
Note this also turns off notifications for hosts and moderators. Only administrators will be able to access a member list with the date that new members joined.