|Open||None||T125653 Create new types of notifications|
|Open||None||T32750 [Epic] Ping/notify user when username used in an edit summary|
|Invalid||TBolliger||T186657 De-duplicate notifications for reverts|
I test on three different language wikis — Rollbacks and undos link to Special:Contributions and the user talk page, not the userpage and therefore will not trigger a edit summary mention notification unless the user performing the undo manually types a link to the username. Therefore, I do not believe we need to do and de-duplication of notifications.