Admin menu Jetpack is visible for users

The menu is indeed visible so users can link their account to their WordPress.com account to use features like Toolbar Notifications.

They can’t activate or deactivate modules, though, you can rest assured! ??

If you don’t want registered users to connect their account to their WordPress.com account, you can hide that menu by adding the following code to your theme’s functions.php file, or to a functionality plugin:

function jp_rm_menu() {
    if( class_exists( 'Jetpack' ) && !current_user_can( 'manage_options' ) ) {
        // This removes the page from the menu in the dashboard
        remove_menu_page( 'jetpack' );
    }
}
add_action( 'admin_menu', 'jp_rm_menu', 1001 );