Are there hooks for WordPress updates?

Yes, there is a hook you can use, it’s called upgrader_process_complete. This hook fires after plugins or core has been upgraded.

You can hook to this action and send an email:

function send_custom_email( $object, $options ) {
    // Get the path for plugins
    $plugin_path = plugin_basename( __FILE__ );
    // Check if the plugin is upgraded
    if ($options['type'] == 'plugin' && $options['action'] == 'update' ){
        foreach($options['packages'] as $plugin){
            if ($plugin == $plugin_path){
            // Do some stuff here
            }
        }
    }
}

add_action( 'upgrader_process_complete', 'send_custom_email',10, 2);

This function allows you to do whatever you want whenever a plugin is updated. You can do so with the core updates, too.