[CF1] testing access policies (#21167)

Author: deadlypants1973

src/content/docs/cloudflare-one/policies/access/policy-management.mdx

@@ -50,6 +50,8 @@ To delete a reusable Access policy:
 
 You can test your Access policies against all existing user identities in your Zero Trust organization.  For the policy tester to work, users must have logged into the [App Launcher](/cloudflare-one/applications/app-launcher/) or any other Access application at some point in time.
 
+Cloudflare will use the most recent device that was authenticated with Access to test your policies. 
+
 ### Test a single policy
 
 The Access policy builder allows you to test your rules before saving any changes.