WordPress at a glance
function is not described

_update_blog_date_on_post_delete() WP 3.4.0

Handler for updating the current site's last updated date when a published post is deleted.

No Hooks.

Return

Nothing (null).

Usage

_update_blog_date_on_post_delete( $post_id );
$post_id(int) (required)
Post ID

Code of update blog date on post delete: wp-includes/ms-blogs.php WP 5.2.2

<?php
function _update_blog_date_on_post_delete( $post_id ) {
	$post = get_post( $post_id );

	$post_type_obj = get_post_type_object( $post->post_type );
	if ( ! $post_type_obj || ! $post_type_obj->public ) {
		return;
	}

	if ( 'publish' != $post->post_status ) {
		return;
	}

	wpmu_update_blogs_date();
}