This action can be for deleting the comment caches. In most cases, the do_action should be done to allow the wpDiscuz to delete its own caches.
Changelog
since 7.3.0 version
Parameters
$post_id – the ID of the post, where the caches should be updated. If it’s missing it’ll work for all posts.
Usage
do_action("wpdiscuz_reset_comments_cache", $post_id);