It's default value in case a user wouldn't provide URLs to Media Services. The actual endpoint URI is configurable through $connectionString passed to createServiceManagementService($connectionString) method of ServicesBuilder class. Please see https://github.com/VladimirTsyshnatiy/ykennor-786/blob/ms-connect/WindowsAzure/Common/ServicesBuilder.php

The same technique is used for Service Management Service so I assumed that it is OK.