Steps to reproduce :
1. Create UserA.
2. Enable UserA to manage entries in Announcements portlet (for example, add Announcements portlet to UserA's My Private Pages).
3. Create a regular organization TestOrg1 without Create Site check (not to create organization site).
4. Assign UserA to TestOrg1 and assign Organization Owner role to UserA.
5. login as UserA.
6. In Announcements portlet, click "Manage Entries" and click "Distribution Scope" dropdown list.
Result: Nonexistent site TestOrg1 is displayed in "Sites" section. TestOrg1 is an only organization.