Stop WordPress From Automatically Installing New Themes

When a major WordPress update is released and installed on your website, the update also installs the lastest version of a default theme (they’re always named starting with the “twenty” pattern).

These automatically get installed in your Theme directory.  Even if you aren’t using any of these themes, they take up space on your server and you will still get update reminders.

You can stop WordPress from installing a theme that is bundled with an update by modifying your wp-config.php file to include the following line:

define('CORE_UPGRADE_SKIP_NEW_BUNDLED' , true);