What are my alternatives to disable update notifications but without using module Update Notifications Disable?
The method below will stop the "available update" emails Drupal admins receive.


Go here: http://yourwebsite.com/admin/reports/updates/settings
Remove your email(s) from the textarea: "E-mail addresses to notify when updates are available"
Save


Note: If you want to stop the "available updates" emails and the update alert messaging then simply disable the update module from http://yourwebsite.com/admin/modules