We are working on the supervisory structure specific to each library. The MLIS will not be required for all supervisory positions. See the career track [1] document available on the Alignment Project page [2] on the intranet for more information about the non-MLIS management track.
Links:
[1] http://my.metrolibrary.info/drupal/sites/default/files/documents/career%20tracks.pdf
[2] http://my.metrolibrary.info/drupal/alignment