Hi Alec
Thanks for reaching out.
Updates to Drupal 9 are indeed rolled out centrally by us with no action necessary from you. However, we are doing these in batches alphabetically, and so while we have updated the vast majority of websites (see https://drupal-community.web.cern.ch/t/which-cern-websites-have-already-upgraded-to-drupal-9/1357), more websites are still pending. If you do not see your website(s) on the above list, they will be updated after the Christmas break. We are not updating any more websites today nor tomorrow.
Thanks!