Organization Managers will no longer have implicit Admin-level access for repositories in which they have been given explicit Read (or more) access. They will now need to be assigned a higher level if required. The change may be a breaking one that requires action on your part but brings it in line with intent.
A Manager user is intended to have privileges to manage org settings, teams, and other users. Access to repositories is not implicit "by default." To change that, you must set it in the Default Object Privileges setting, or the Manager user can be given direct access via a repository's Access Controls setting.
This change does not affect a Manager user's intended privileges, as outlined above. If you need any help or advice with this change, or if this affects you in an unintended way, please don't hesitate to contact us for assistance. We'd be delighted to help!