How does the Disable All option affect WordPress Automatic Updates?
Note: This option is no longer applicable to the latest version of the Shield Security plugin and is here for reference purposes only.
This option will completely prevent any and all WordPress Automatic Updates.
It overrides every other option on the Automatic Updates section of the plugin and in most cases any other plugin that is adjusting your automatic updates.
When you turn this option on, you turn off all automatic updates for the site. Period.