Add a tag to just add users.

playbooks/edx-east/ad_hoc_reporting.yml

+# Creating a new ad hoc reporting box:
+# ansible-playbook -i 'reporting.example.com,' ./ad_hoc_reporting.yml -e@/var/path/common.yml -e@/vars/path/environnment-deployment.yml
+# Updating the users on an existing box:
+# ansible-playbook -i 'reporting.example.com,' ./ad_hoc_reporting.yml --tags users -e@/var/path/common.yml -e@/vars/path/environnment-deployment.yml
 - name: Deploy Ad Hoc Reporting Scripts 
   hosts: all
   sudo: True

playbooks/roles/ad_hoc_reporting/meta/main.yml

@@ -13,4 +13,6 @@
 dependencies:
   - role: user
     user_info: "{{ AD_HOC_REPORTING_USER_INFO }}"
+    tags:
+      - users
   - aws