change default 'post' slug with register_post_type_args

Question

I'm trying to change the default slug for default wordpress post.

With register_post_type works fine with this code:

add_action( 'init', 'my_new_default_post_type', 1 );
function my_new_default_post_type() {

    register_post_type( 'post', array(          
        'rewrite' => array( 'slug' => 'blog' ),         
    ) );
}

But with recent register_post_type_args is not possible. This is my code:

add_filter( 'register_post_type_args', 'new_register_post_type_args', 10, 2 );
function new_register_post_type_args( $args, $post_type ) {

    if ( 'post' === $post_type ) {      

        $args['rewrite']['slug'] = 'blog';

    }

    return $args;
}

Any ideas?