The message notification-bundle-header-edit-user-talk currently says:
$1 and $4 {{PLURAL:$5|other|others}} {{GENDER:$2|left}} a message on {{GENDER:$3|your}} talk page.
If I understand correctly, {{GENDER:$2|left}} refers to at least two people who left a message, and in this case the gender is probably irrelevant, because it is only useful for describing one person.
There are similar issues with notification-bundle-body-flow-post-reply and notification-bundle-header-flow-post-edited.