The discussion revolves around the behavior of edit notifications in private messages (PMs) on Discourse. Nacho_Caballero initially pointed out that editing a PM doesn’t generate a notification, unlike regular posts. sam questioned whether this was a bug or intended behavior, suggesting that moderators might not want users notified.
Nacho_Caballero clarified that they found the behavior surprising due to the visual edit indicator being the same as regular posts. They also mentioned a separate issue with the edit button label changing from “Save edit” to “Message” after a recent update.
CvX reported a similar regression in editing whispers, which was confirmed by codinghorror to be an issue. However, codinghorror believes that editing a whisper should generate a notification, unlike PMs.
Nacho_Caballero clarified that the discussion was separate from the notification issue, focusing on the button label language. Osama addressed the regression and provided a PR to fix the issue.
On regular topics, editing someone else’s post generates an ‘edited’ notification (notification_type: 4).
However, if the topic is a PM, the edited pencil appears (because a post_revision is generated) but the recipient is not notified and no notification appears in /notifications/edits.
Hmmm, is this a bug … or a feature request.
Only editors in that case would be mods, maybe they don’t want the users notified?
Fair enough. I wasn’t sure if it was the intended behavior or not.
I just found it surprising when I found out that PM edits didn’t behave like regular post edits because the visual edit indicator was the same.
Along the same lines, I think some weeks ago, when editing someone else’s PM, the button would display “Save edit”, but after a recent update it now displays “Message”, which is confusing since the message has already been sent. 
The only other alternative I can think of is that there’s a problem with the translation (my site is in Spanish).
Oh, I just noticed the same while editing a whisper, but I wasn’t sure if it used to say “Save edit” or anything other than “Whisper”.
That regressed in UX: Composer actions menu should display the icon of selected action by OsamaSayegh · Pull Request #12449 · discourse/discourse · GitHub
I think the desired UI is “icon + save edit label” in those cases.
cc: @Osama
Editing a whisper should generate a notification, but not a PM. I agree with @sam.
Thanks, Jeff. Yes, I agreed here.
What Jarek and I were referring to is something else related to the language in the buttons when editing (regardless of the notification).
Thanks for letting us know! This PR should fix this regression: