As announced in the newsletter of 29 June, a new blocker step will be inserted in the pipeline for all Drupal 8 sites as of 15 October. It will block deployment with possibility of bypass in order to raise awareness of the need to upgrade to Drupal 9. From 1 December, no new deployments for Drupal 8 sites will be possible: sites will need to upgrade to Drupal 9 in order to proceed with a deployment.