About [[MediaWiki:Notification-edit-talk-page-bundle/ksh]]
Fragment of a discussion from Translating talk:MediaWiki
See also notification-edit-user-talk-email-batch-bundle-body ("$1 and {{PLURAL:$2|one other|$2 others|100=99+ others}} {{GENDER:$1|left}} a message on your talk page.").
Filed as phab:T125264. Very sorry about the long delay. (I'm not sure whether it's practical to get the exact number of messages (or rather, how much extra backend code and processing that would take) hence filed on phabricator for the devs to contemplate).