Exclude certain categories from main blog without Child theme?

Replies: 1

In my 2011 theme, I made a child theme
I edited functions.php

function exclude_category($query) {
	if ( $query->is_home ) {
		$query->set('cat', '-68 -69 -70 -71');
	}
	return $query;
}
add_filter('pre_get_posts', 'exclude_category');

Is this the same if I am using WP 5.6 and 2020 theme?