// Mark site as no longer fresh
foreach ( array( 'publish_post', 'publish_page', 'wp_ajax_save-widget', 'wp_ajax_widgets-order', 'customize_save_after' ) as $action ) {
    add_action( $action, '_delete_option_fresh_site', 0 );
}

function wpse_340803_keep_setup_wizard_fresh() {
    if ( isset( $_GET['page'] ) && 'wc-setup' === $_GET['page'] ) {
        foreach ( array( 'publish_post', 'publish_page', 'wp_ajax_save-widget', 'wp_ajax_widgets-order', 'customize_save_after' ) as $action ) {
            remove_action( $action, '_delete_option_fresh_site', 0 );
        }
    }
}
add_action( 'admin_init', 'wpse_340803_keep_setup_wizard_fresh', 0 );