Uninstalling

Deactivating stops the scheduled work and leaves everything else alone, so switching the plugin off to test a theme does not lose your subscribers. Reactivating books it again, and runs what fell due in between. A switch-off time that went by more than a week before switches the mode off and emails nobody, and the Dashboard offers Send the launch email, which asks first.

Deleting removes data only if you ticked Delete all data on uninstall under Settings. It is off by default. The page shown during WordPress updates, wp-content/maintenance.php, is removed on deactivating and on deleting either way, since without the plugin nobody could change or remove it.