Thank you Ben.
You already realized it. I will also suggest completely avoiding pre_get_posts as it will have side effect.

It will better to directly modify the template in this case. If you still want to use pre_get_posts, I suggest pairing it with the following conditions

if ( function_exists( 'bp_is_buddyblog_component' ) && bp_is_buddyblog_component() ) {

}

Regards
Brajesh

Please do let me know when you have the details.

Sorry about that. I was cleaning before update and I had used it for somereason instead of the correct one(bpp_get_topic_permalink).

Please re download it. I have pushed the change.

Thank you
Brajesh

Hi,
Please use the code from here

/**
 * Display the name of the creator of the gallery below gallery cover
 *
 */
function mpp_custom_display_gallery_owner_name() {
	$gallery = mpp_get_gallery();
	if ( ! $gallery ) {
		return ;
	}
	printf(  'by: %s',  bp_core_get_userlink( $gallery->user_id ) );
}
add_action( 'mpp_gallery_shortcode_item_meta', 'mpp_custom_display_gallery_owner_name' );

For other cases, you may take a look at the code here
https://gist.github.com/sbrajesh/b47b84c3fdca9b76f04e696894a80d06

We will be pushing the changed code(sorry, we missed the last deadline), hopefully this sunday too.
Thank you. We will keep you informed.

Regards
Brajesh

Hi,
I have created a small plugin for you(It does not handle topic deletion yet)
https://github.com/buddydev/bbp-bp-notify-new-topic

Please use the plugin and it will work as expected.

Hope that helps.

Regards
Brajesh