Comment 1 for bug 1628891

Well, the changelog leads one to believe it should work although I haven't found any code that actually checks that directory.

update-manager (1:0.99) jaunty; urgency=low

  [ Michael Vogt ]
  * DistUpgrade/DistUpgradeController.py:
    - enable apport crash capturing during upgrades
  * DistUpgrade/DistUpgradeView.py:
    - create /var/lib/pycentral/pkgremove before the upgrade to
      help pycentral transition to the new python policy (thanks
      to doko)
  * ensure pidgin-libnotify is upgraded (LP: #332328)
  * better wording for aborts (thanks to Gabor Kelemen and
    Jean-Baptiste Lallement), LP: #289303
  * wording fixes, thanks to Brian Murray and Gabor Kelemen
    LP: #269583
  * i18n fix, thanks to Gabor Kelemen, LP: #331821
  * support /etc/update-manager/release-upgrades.d/ directory
    for local overrides of the upgrade process. Useful to force
    certain site-specific options (like third party repository
    handling)