Add effective date to Oct 28 release note

Author: jpipkin1

blog-cse/2025-10-28-content.md

@@ -12,7 +12,7 @@ This content release includes:
     - Updates to existing mappers for Crowdstrike Falcon, F5, and Okta events to support additional fields and events.
     - Updates to F5 Networks and Okta SSO parsers.
 
-Changes are enumerated below.
+This new and updated content is effective as of October 22, 2025. Changes are enumerated below.
 
 ### Log Mappers
 - [New] CrowdStrike Falcon Host API IdpDetectionSummaryEvent