Currently, there are two levels of suppression, blocking non-admin viewing and blocking non-admin/admin viewing.
If a revision or log entry is hidden from non-admins, admins must have the "deleterevision" user right in order to see the suppressed data. However, there's no way to give users the ability to _see_ suppressed data but not actually be able to suppress data themselves.
A new user right should be added that allows users to only have view access for suppressed content. The "deleterevision" user right should continue to allow view and act access (as it does currently).