BuddyPress.org

Nope. That function is the beginning of a series of things that happens. The function that actually send out the emails is: groups_notification_group_invites() in /mu-plugins/bp-groups/bp-groups-notifications.php

Let me guess, you want to disable it there? Line 261 of that function is:

wp_mail( $to, $subject, $message );

Comment that out and no group invite email will ever leave your box.