On the "Available translation updates" page (admin/reports/translations) the translation updates don't work if the Update Manager module is disabled. There is no notification for the user to enable the module to make translation updates work. Right now user sees following message in this case:
"No translation status available. Check manually."
It doesn't make sense, because checking manually doesn't do anything, even if the translation files for importing are in files directory. The message should at least include information that the Update Manager module needs to be enabled to make translation updates work.