See linked discussion.
If we mark the edit as a bot in the user talk namespace, the user will still receive a notification. But if we post on some other page, it'll get hidden from user's watchlists/RC, which is not what we want.
Version: unspecified
Severity: normal
Whiteboard: gci2014
URL: https://meta.wikimedia.org/wiki/Talk:MassMessage#Watchlist